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Sample records for southern african river

  1. Southern African Business Review

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited scientific journal of the College of Economic and Management Sciences of the .... The effects of extended water supply disruptions on the operations of SMEs · EMAIL FREE ...

  2. Southern African Business Review

    African Journals Online (AJOL)

    Southern African Business Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 1 (2016) >. Log in or Register to get access to full text downloads.

  3. Southern African Business Review: Submissions

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited journal of the College of Economic and Management Sciences of the University of South Africa. ... the right to make minor editorial adjustments without consulting the author.

  4. Southern African Journal of Environmental Education

    African Journals Online (AJOL)

    The Southern African Journal of Environmental Education (SAJEE) is an accredited and ... It is published at least once a year, by the Environmental Education Association of Southern Africa (EEASA). ... AJOL African Journals Online. HOW TO ...

  5. Review of Southern African Studies: Journal Sponsorship

    African Journals Online (AJOL)

    Review of Southern African Studies: Journal Sponsorship. Journal Home > About the Journal > Review of Southern African Studies: Journal Sponsorship. Log in or Register to get access to full text downloads.

  6. Review of Southern African Studies

    African Journals Online (AJOL)

    Review of Southern African Studies is a multidisciplinary journal of Arts, Social and Behavioural Sciences. Vol 13, No 1 (2009). DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Table of Contents. Articles. Health-Care Waste Practices in Selected Health-Care Facilities in Maseru ...

  7. Southern African Journal of Environmental Education

    African Journals Online (AJOL)

    ... knowledge and community based management of wildlife resources: a study of the Mumbwa and Lupande Game Management areas of Zambia. ... Southern African Journal of Environmental Education ... AJOL African Journals Online.

  8. A Southern African positron beam

    International Nuclear Information System (INIS)

    Britton, D.T.; Haerting, M.; Teemane, M.R.B.; Mills, S.; Nortier, F.M.; Van der Walt, T.N.

    1997-01-01

    The first stage of a state of the art positron beam, being constructed at the University of Cape Town, is currently being brought into operation. This is the first positron beam on the African continent, as well as being the first positron beam dedicated to solid and surface studies in the southern hemisphere. The project also contains a high proportion of local development, including the encapsulated 22 Na positron source developed by our collaboration. Novel features in the design include a purely magnetic in-line deflector, working in the solenoidal guiding field, to eliminate unmoderated positrons and block the direct line of sight to the source. A combined magnetic projector and single pole probe forming lens is being implemented in the second phase of construction to achieve a spot size of 10 μm without remoderation

  9. South African southern ocean research programme

    CSIR Research Space (South Africa)

    SASCAR

    1987-01-01

    Full Text Available This document describes the South African National Antarctic Research Programme's (SANARP) physical, chemical and biological Southern Ocean research programme. The programme has three main components: ecological studies of the Prince Edward Islands...

  10. Southern African Business Review: Editorial Policies

    African Journals Online (AJOL)

    The Southern African Business Review is a refereed and accredited scientific ... Accounting, Public Management, Tourism Management and related fields. ... This journal provides immediate open access to its content on the principle that ...

  11. Globalisation, transport and HIV | Andrews | Southern African ...

    African Journals Online (AJOL)

    No Abstract Southern African Journal of HIV Medicine Vol. 5 (4) 2004: 41-44. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL ...

  12. Geoconservation - a southern African and African perspective

    Science.gov (United States)

    Reimold, Wolf Uwe

    1999-10-01

    In contrast to Europe, where geoconservation is actively pursued in most countries and where two international symposia on this subject have been staged in 1991 and 1996, geoconservation in Africa has indeed a very poor record. Considering the wealth of outstanding geological sites and the importance African stratigraphy has within the global geological record, pro-active geoconservation on this continent has not featured very prominently to date. In the interest of science, education and tourism, unique and typical geosites need to be identified, catalogued, and prioritised with the aim being their protection. Most African countries do not have vibrant non-governmental organisations such as a strong geological society, which could drive projects like geoconservation, or strong support from the private sector for environmental work. Here, a case is made for the role that established National Geological Surveys, some of which are already involved with retroactive environmental geological work, could play in the forefront of pro-active geoconservation and site protection.

  13. Towards a Southern African English Defining Vocabulary

    African Journals Online (AJOL)

    user

    of parameters, such as avoiding synonyms and antonyms, to determine which words are necessary to write definitions in a concise and simple way. It has been found that existing defining vocabularies lack certain words that would make definitions more accessible to southern African learners, and therefore there is a need ...

  14. Globalisation, transport and HIV | Andrews | Southern African ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 5, No 4 (2004) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected ...

  15. Review of Southern African Studies: Submissions

    African Journals Online (AJOL)

    Author Guidelines. 1. Every manuscript should be accompanied with a statement that it has not been submitted for publication elsewhere. 2. The Review of Southern African Studies prefers articles which cut across disciplinary boundaries. Articles with narrow foci and incomprehensible to people outside those disciplines ...

  16. Review of Southern African Studies: Editorial Policies

    African Journals Online (AJOL)

    Editorial Board. Prof. R.C. Leduka Institute of Southern African Studies, NUL. Dr. F. Baffoe Baffoe and Associates, Maseru. Prof. Q. Chakela National University of Lesotho. Prof. L.B.B.J. Machobane Machobane and Associates, Maseru. Prof. E.M. Sebatane National University of Lesotho. Dr. E. Obioha National University of ...

  17. THE ORIGINS OF THE SOUTHERN AFRICAN MAMMAL FAUNA ...

    African Journals Online (AJOL)

    Southern Africa can be geographically subdivided into different biotic zones, differing from .... The greater part of the southern African mammal fauna consists of savanna .... spread into southern Africa by way of the Savanna biotic zone.

  18. SAFERE: Southern African Feminist Review

    African Journals Online (AJOL)

    Feminism and Masculinity in an African Capitalist Context: · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Mwenda G. Ntarangwi, 19-32. http://dx.doi.org/10.4314/safere.v3i1.23948 ...

  19. Ecological flow requirements for South African rivers

    CSIR Research Space (South Africa)

    Ferrar, AA

    1989-01-01

    Full Text Available This document contains the proceedings of a workshop which was convened to debate the ecological flow requirements of South African rivers. Topics which are discussed include the influence of weirs and impoundments, the quantity requirements...

  20. Studies of mineralization in South African rivers

    CSIR Research Space (South Africa)

    Hall, GC

    1978-03-01

    Full Text Available Several South African rivers are polluted by mineral salts of diffuse source. This pollution can be related to geological phenomena and to irrigation practices. Mineralization is problematic in that it can render surface waters unsuitable...

  1. Aspidonepsis (Asclepiadaceae, a new southern African genus

    Directory of Open Access Journals (Sweden)

    A. Nicholas

    1992-10-01

    Full Text Available Aspidonepsis, an endemic southern African genus, is described and compared to the closely allied genus Aspidoglossum. This newly described genus is composed of two subgenera, Aspidonepsis and Unguilobium. consisting of three and two species respectively.  Asclepias diploglossa, A. flava, A. cognata and A. reneensis are transferred to Aspidonepsis. and A. shebae is newly described. All species are discussed, illustrated and a key is given to aid in their identification.

  2. AIDS Prevention in the Southern African Development Community ...

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

    AIDS Prevention in the Southern African Development Community : Policy Research and Decision Support. The Southern African Development Community (SADC) is at the epicentre of the AIDS pandemic. The regional adult HIV prevalence is approximately 11%, twice the average in other African countries. Scores of ...

  3. Ecological Research on South African rivers - a preliminary synthesis

    CSIR Research Space (South Africa)

    O'Keeffe, JH

    1986-01-01

    Full Text Available Ecological research on South African rivers has progressed in a number of phases. Until 1950 work was mainly taxonomic and descriptive, an essential prerequisite for more detailed studies. The realisation that South African rivers, a vital national...

  4. Conservation of South African Rivers

    CSIR Research Space (South Africa)

    O'Keeffe, JH

    1986-01-01

    Full Text Available The report presents the proceedings of a three-day workshop at Midmar Dam designed to establish a consensus view of river conservation and to provide professional conservationists, managers and planners with a set of guidelines. These indicate what...

  5. Southern African Journal of Environmental Education - Vol 8 (1988)

    African Journals Online (AJOL)

    Southern African Journal of Environmental Education - Vol 8 (1988) ... An interaction of archaeology with school history in a museum education context ... The child in the outdoor classroom · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  6. Academic publishing: Lessons learnt from the Southern African ...

    African Journals Online (AJOL)

    Key words: academic publishing, peer review, Southern African Business Review ... Management Sciences of Unisa, for example, 16.5% of academics ..... as scientific field of manuscript; to number, origin and designation of authors; and.

  7. Environmental education and quality of life | Bak | Southern African ...

    African Journals Online (AJOL)

    Southern African Journal of Environmental Education. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 17 (1997) >. Log in or Register to get access to full text downloads.

  8. Southern African Business Review - Vol 21, No 1 (2017)

    African Journals Online (AJOL)

    Southern African Business Review - Vol 21, No 1 (2017) ... Pre-packaged applications in business reorganisations: International principles · EMAIL ... Microcredit supply under Islamic Banking in Khartoum State, Sudan · EMAIL FREE FULL ...

  9. Southern African Linguistics and Applied Language Studies - Vol 31 ...

    African Journals Online (AJOL)

    Southern African Linguistics and Applied Language Studies. ... Object marking restrictions on Shona causative and applicative constructions · EMAIL ... A problem-oriented, form-focused course design for teaching isiZulu as an additional ...

  10. A nurse's perspective on the ART rollout | Tito | Southern African ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2014) >. Log in or Register to get access to full text downloads.

  11. Reflections on six years in paediatric ART | Moore | Southern African ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 15, No 1 (2014) >. Log in or Register to get access to full text downloads.

  12. Patterns of endemicity and range restriction among southern African ...

    African Journals Online (AJOL)

    Patterns of endemicity and range restriction among southern African coastal marine invertebrates. RJ Scott, CL Griffiths, TB Robinson. Abstract. Southern Africa supports a rich marine biota of 12 734 currently described marine species. Although the distribution and overall species-richness patterns of several component ...

  13. The Southern African Large Telescope project

    Science.gov (United States)

    Buckley, David A. H.; Charles, Philip A.; Nordsieck, Kenneth H.; O'Donoghue, Darragh

    The recently completed Southern African Large Telescope (SALT) is a low cost, innovative, 10 m class optical telescope, which began limited scientific operations in August 2005, just 5 years after ground-breaking. This paper describes the design and construction of SALT, including the first-light instruments, SALTICAM and the Robert Stobie Spectrograph (RSS). A rigorous systems engineering approach has ensured that SALT was built to specification, on budget, close to the original schedule and using a relatively small project team. The design trade-offs, which include an active spherical primary mirror array and a fixed altitude telescope with a prime focus tracker, although restrictive in comparison to conventional telescopes, have resulted in an affordable 10 m class telescope for South Africa and its ten partners. Coupled with an initial set of two seeing-limited instruments that concentrate on the UV-visible region (320 - 900 nm) and featuring some niche observational capabilities, SALT will have an ability to conduct some unique science. This includes high time resolution studies, for which some initial results have already been obtained. Many of the versatile modes available with the RSS - which is currently being commissioned - are unique and provide unparallelled opportunities for imaging polarimetry and spectropolarimetry. Likewise, Multi-Object Spectroscopy (with slit masks) and imaging spectroscopy with the RSS, the latter using Fabry-Perot étalons and interference filters, will extend the multiplex advantage over resolutions from 300 to 9000 and fields of view of 2 to 8 arcminutes. Future instrumentation plans include an extremely stable, fibre-fed, high resolution échelle spectrograph and a near-IR (to between 1.5 to 1.7 μm) extension to the RSS. Future development possibilities include phasing the primary mirror and AO. Finally, extrapolations of the SALT/HET designs to ELT proportions remain viable and are surely more affordable than conventional

  14. Completion of the Southern African Large Telescope

    Science.gov (United States)

    Buckley, D. A. H.; Charles, P. A.; O'Donoghue, D.; Nordsieck, K. H.

    2006-08-01

    The Southern African Large Telescope (SALT) is a low cost (19.7M), innovative, 10-m class optical telescope, which was inaugurated on 10 November 2005, just 5 years after ground-breaking. SALT and its first-light instruments are currently being commissioned, and full science operations are expected to begin later this year. This paper describes the design and construction of SALT, including the first-light instruments, SALTICAM and the Robert Stobie Spectrograph (RSS). A rigorous Systems Engineering approach was adopted to ensure that SALT was built to specification, on budget, close to the original schedule and using a relatively small project team. The design trade-offs, which include an active spherical primary mirror array in a fixed altitude telescope with a prime focus tracker, although restrictive in comparison to conventional telescopes, have resulted in an affordable and capable 10-m class telescope for South Africa and its ten partners. Coupled with an initial set of two seeing-limited instruments that concentrate on the UV-visible region (320 - 900nm) and featuring some unique observational capabilities, SALT will have an ability to conduct a wide range of science programs. These will include high time resolution studies, for which some initial results have already been obtained and are presented here. Many of the versatile modes available with the RSS will provide unparalleled opportunities for imaging polarimetry and spectropolarimetry. Likewise, Multi-Object Spectroscopy (using laser cut graphite slit masks) and imaging spectroscopy with the RSS, the latter using Fabry-Perot etalons and interference filters, will extend the multiplex advantage over resolutions from R = 300 to 9000 over fields of view of 2 to 8 arcminutes. Future instrumentation plans include an extremely stable, fibre-fed, high resolution échelle spectrograph and a near-IR (possibly to 1.7 μm) extension to the RSS. Future development possibilities include phasing the primary mirror

  15. Characteristics of southern California atmospheric rivers

    Science.gov (United States)

    Harris, Sarah M.; Carvalho, Leila M. V.

    2018-05-01

    Atmospheric rivers (ARs) are channels of high water vapor flux that transport moisture from low to higher latitudes on synoptic timescales. In areas of topographical variability, ARs may lead to high-intensity precipitation due to orographic forcing. ARs landfalling along North America's west coast are linked to extreme events including those leading to flooding and landslides. In southern California (SCA), proper AR forecasting is important for regional water resources as well as hazard mitigation and as the area's annual precipitation totals occur from relatively few storms per season, any changes to storm frequency and/or intensity may have dramatic consequences. Yet, as most regional AR studies focus on the Pacific Northwest, there is little information about SCA ARs. We develop an algorithm to identify ARs landfalling on North America's west coast between 1979 and 2013 within total precipitable water reanalysis fields. ARs are then categorized according to landfall region. To determine and differentiate the characteristics and spatial distributions of ARs affecting these areas, we examine lag composites of various atmospheric variables for each landfall region. SCA ARs differ from ARs landfalling farther north in the days prior to landfall with the position and amplitude of a trough offshore from the Asian continent and ridge over Alaska, as well as the displacement and eastward extension of the jet core that potentially guides AR moisture southwards. The relationships between AR landfalls and the El Niño/Southern Oscillation (ENSO), the Madden-Julian Oscillation (MJO), and the Pacific/North American Teleconnection Pattern (PNA) are also investigated.

  16. Southern African Development Research Network | IDRC ...

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

    ... to craft policies for fruitful integration into the global economy and inclusive growth. ... The grant will support a broad-based research network, the Southern Africa ... researchers based in regional institutions; transforming selected institutions ...

  17. AIDS in Zimbabwe: | Sibanda | SAFERE: Southern African Feminist ...

    African Journals Online (AJOL)

    SAFERE: Southern African Feminist Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 1 (1999) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. DOWNLOAD FULL TEXT Open Access ...

  18. Starting infants on antiretroviral therapy | Clayden | Southern African ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 9, No 4 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected ...

  19. Extension systems in Southern African countries: A review | Oladele ...

    African Journals Online (AJOL)

    This paper reviews extension systems in selected southern African countries with a view of identifying the features of the systems and how they have been able to reach their target audience. Some of the features are use of committees for research and extension linkages, involvement of NGOs and private sector, the use ...

  20. Post-exposure prophylaxis | Smith | Southern African Journal of HIV ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 2, No 1 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Post-exposure prophylaxis. C Smith. Abstract.

  1. Southern African Regional Science Initiative (SAFARI 2000): wet season campaigns

    CSIR Research Space (South Africa)

    Otter, LB

    2002-03-01

    Full Text Available The Southern African Regional Science Initiative (SAFARI 2000) involved two wet season and one dry season field campaigns. This paper reports on the wet season campaigns. The first was conducted at five sites along the Kalahari Transect in Zambia...

  2. Extra-territorial African police and soldiers in Southern Rhodesia ...

    African Journals Online (AJOL)

    Southern Rhodesia were dominated by African men from neighbouring territories such as Nyasaland, Northern Rhodesia and Portuguese East Africa who had entered the regional migrant labour system. This included many with previous military experience. As the British South Africa Police (BSAP) evolved from a ...

  3. Editorial | Michell | Southern African Journal of Critical Care

    African Journals Online (AJOL)

    Southern African Journal of Critical Care. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 32, No 2 (2016) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Editorial. Lance Michell. Abstract. Care or burn in ...

  4. Lifebox | Wilson | Southern African Journal of Anaesthesia and ...

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 18, No 1 (2012) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Lifebox. IH Wilson. Abstract.

  5. Lifebox | Wilson | Southern African Journal of Anaesthesia and ...

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 18, No 1 (2012) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF ...

  6. Echolocation caBs of twenty southern African bat species

    African Journals Online (AJOL)

    all species, and added that intensity and harmonic information. (not available through ANABAT recordings) would have proved useful for identification. The aim of this study is to present new echolocation data for. 20 southern African species using a time-expansion Petters- son D980 bat detector, particularly with the view to ...

  7. Editorial | Borges | Southern African Journal of Anaesthesia and ...

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 23, No 3 (2017) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF ...

  8. Mass-Produced, Buffer | Masitera | SAFERE: Southern African ...

    African Journals Online (AJOL)

    SAFERE: Southern African Feminist Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 2 (1999) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. DOWNLOAD FULL TEXT Open Access ...

  9. Salinity ranges of some southern African fish species occurring in ...

    African Journals Online (AJOL)

    The recorded salinity ranges of 96 fish species occurring in southern African estuaries are documented. Factors influen- cing the tolerance of fishes to low and high salinity regimes are discussed, with most species tolerant of low rather than high salinity conditions. This is important since most systems are subject to periodic ...

  10. Running the rat race | Pearce | Southern African Journal of ...

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 1 (2014) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF ...

  11. Running the rat race | Pearce | Southern African Journal of ...

    African Journals Online (AJOL)

    Southern African Journal of Anaesthesia and Analgesia. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 1 (2014) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Running the rat race. W Pearce ...

  12. One being White | Newman | SAFERE: Southern African Feminist ...

    African Journals Online (AJOL)

    SAFERE: Southern African Feminist Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 3, No 2 (1999) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. DOWNLOAD FULL TEXT Open Access ...

  13. Competency development of southern African housing officers ...

    African Journals Online (AJOL)

    Abstract. The Report on the Ministerial Committee for the Review of the Provision of Student Housing at South African Universities (Department of Higher Education and Training, 2011) has provided a comprehensive review of residences across several housing functional areas. In one of the residence management and ...

  14. Book Review: Multilingualism online | Roux | Southern African ...

    African Journals Online (AJOL)

    Book Title: Multilingualism online. Book Author: Carmen Lee. 2017. London and New York: Routledge. ISBN 9781138900493. 170 pages. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.2989/16073614.2017.1373369 · AJOL African Journals Online.

  15. Marketing University Education: The Southern African Experience.

    Science.gov (United States)

    Maringe, Felix; Foskett, Nick

    2002-01-01

    Examined the perceptions of university marketers in southern Africa. Found a varying awareness of the significance of marketing, with more mature institutions exhibiting more developed marketing orientations. Strategies ranged from marketing as public relations to marketing as sales, with universities in South Africa the only ones demonstrating a…

  16. Zoogeography of the southern African echinoderm fauna

    African Journals Online (AJOL)

    1988-04-17

    Apr 17, 1988 ... Pertinent features of the oceanography of southern Africa are reviewed and an analysis of the echinoderm fauna in relation to the genera] ..... five extant echinoderm classes (all species). Crinoids. Asteroids Ophiuroids .... Australia and New Zealand, which are included with. R eprod u ced by Sabin et G.

  17. Resource reviews | Naude | Southern African Journal of ...

    African Journals Online (AJOL)

    Petro Naude. Walk through the wilderness by Don Richards and Clive. Walker. Published by Endangered Wildlife Trust and Wilderness Trust of Southern Africa, Johannesburg. Second (revised) edition 1986. 146 pp., photographs, maps, charts and line drawings. Price R9,95. 2. Pat Irwin. Trout in South Africa edited by P.H. ...

  18. Southern African advanced fire information system

    CSIR Research Space (South Africa)

    McFerren, G

    2009-05-01

    Full Text Available of ecosystems, yet fires threaten natural systems, infrastructure and life. Spatio-temporal awareness of fire likelihood, occurrence and behaviour is key to appropriate prevention, response and management. This paper focuses on wildfire risk to infrastructure... to pinpoint the location and possibly information on fire temperature and size. Previously, Eskom line managers depended on local residents for necessary information about fire occurrences and locations. Eskom and CSIR, a South African research institute...

  19. Testing times for Southern African exports

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-15

    With South African coal exports projected to increase by more than 35% over the next decade, will the development of the country's infrastructure be ready? A combination of derailments, bad weather and a lack of capacity on the Transnet Freight Rail (TFR) rail network seriously curtailed shipments in 2008 and 2009. It had been hoped that Richards Bay Coal Terminal(RPCT) would now be able to make use of its expanded capacity but a serious transport strike may encourage traders to switch to Mozambican ports.

  20. Different cranial ontogeny in Europeans and Southern Africans.

    Directory of Open Access Journals (Sweden)

    Marina L Sardi

    Full Text Available Modern human populations differ in developmental processes and in several phenotypic traits. However, the link between ontogenetic variation and human diversification has not been frequently addressed. Here, we analysed craniofacial ontogenies by means of geometric-morphometrics of Europeans and Southern Africans, according to dental and chronological ages. Results suggest that different adult cranial morphologies between Southern Africans and Europeans arise by a combination of processes that involve traits modified during the prenatal life and others that diverge during early postnatal ontogeny. Main craniofacial changes indicate that Europeans differ from Southern Africans by increasing facial developmental rates and extending the attainment of adult size and shape. Since other studies have suggested that native subsaharan populations attain adulthood earlier than Europeans, it is probable that facial ontogeny is linked with other developmental mechanisms that control the timing of maturation in other variables. Southern Africans appear as retaining young features in adulthood. Facial ontogeny in Europeans produces taller and narrower noses, which seems as an adaptation to colder environments. The lack of these morphological traits in Neanderthals, who lived in cold environments, seems a paradox, but it is probably the consequence of a warm-adapted faces together with precocious maturation. When modern Homo sapiens migrated into Asia and Europe, colder environments might establish pressures that constrained facial growth and development in order to depart from the warm-adapted morphology. Our results provide some answers about how cranial growth and development occur in two human populations and when developmental shifts take place providing a better adaptation to environmental constraints.

  1. Stable isotope content of South African river water

    International Nuclear Information System (INIS)

    Talma, A.S.

    1987-01-01

    Variations of the isotopic ratios 18 O/ 16 O and D/H in natural waters reflect the variety of processes to which the water was subjected within the hydrological cycle. Time series of the 18 O content of the major South African rivers over a few years have been obtained in order to characterise the main features of these variations in both time and space. Regionally the average '1 8 O content of river water reflects that of the prevailing rains within the catchment. 18 O variations with time are mainly correlated with river flow rates. Impoundments upstream and management of river flows reduce this correlation. Isotope variations along the course of a river show the effects of inflow from smaller streams and evaporation in the river or its impoundments. These observations indicate the use of isotopic methods to study the evaporation and mixing of river water and its interaction with the surrounding environment

  2. Water quality assessment of the Sinos River, Southern Brazil.

    Science.gov (United States)

    Blume, K K; Macedo, J C; Meneguzzi, A; Silva, L B; Quevedo, D M; Rodrigues, M A S

    2010-12-01

    The Sinos River basin is located Northeast of the state of Rio Grande do Sul (29º 20' to 30º 10' S and 50º 15' to 51º20'W), Southern Brazil, covering two geomorphologic provinces: the Southern plateau and central depression. It is part of the Guaíba basin and has an area of approximately 800 km², encompassing 32 municipalities. The objective of this study was to monitor water quality in the Sinos River, the largest river in this basin. Water samples were collected at four selected sites in the Sinos River, and the following parameters were analysed: pH, dissolved oxygen, biochemical oxygen demand (BOD₅), turbidity, fecal coliforms, total dissolved solids, temperature, nitrate, nitrite, phosphorous, chromium, lead, aluminum, zinc, iron, and copper. The results were analysed based on Resolution No. 357/2005 of the Brazilian National Environmental Council (CONAMA) regarding regulatory limits for residues in water. A second analysis was performed based on a water quality index (WQI) used by the Sinos River Basin Management Committee (COMITESINOS). Poor water quality in the Sinos River presents a worrying scenario for the region, since this river is the main source of water supply for the urban core. Health conditions found in the Sinos River, mainly in its lower reaches, are worrying and a strong indicator of human activities on the basin.

  3. Water quality assessment of the Sinos River, Southern Brazil

    Directory of Open Access Journals (Sweden)

    KK. Blume

    Full Text Available The Sinos River basin is located Northeast of the state of Rio Grande do Sul (29º 20' to 30º 10' S and 50º 15' to 51º20'W, Southern Brazil, covering two geomorphologic provinces: the Southern plateau and central depression. It is part of the Guaíba basin and has an area of approximately 800 km², encompassing 32 municipalities. The objective of this study was to monitor water quality in the Sinos River, the largest river in this basin. Water samples were collected at four selected sites in the Sinos River, and the following parameters were analysed: pH, dissolved oxygen, biochemical oxygen demand (BOD5, turbidity, fecal coliforms, total dissolved solids, temperature, nitrate, nitrite, phosphorous, chromium, lead, aluminum, zinc, iron, and copper. The results were analysed based on Resolution No. 357/2005 of the Brazilian National Environmental Council (CONAMA regarding regulatory limits for residues in water. A second analysis was performed based on a water quality index (WQI used by the Sinos River Basin Management Committee (COMITESINOS. Poor water quality in the Sinos River presents a worrying scenario for the region, since this river is the main source of water supply for the urban core. Health conditions found in the Sinos River, mainly in its lower reaches, are worrying and a strong indicator of human activities on the basin.

  4. SAFARI 2000 Estimated BVOC Emissions for Southern African Land Cover Types

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: Improved vegetation distribution and emission data for Africa south of the equator were developed for the Southern African Regional Science Initiative...

  5. In vitro determination of the anti-aging potential of four southern African medicinal plants

    CSIR Research Space (South Africa)

    Ndlovu, G

    2013-11-01

    Full Text Available southern African medicinal plants; Clerodendrum glabrum, Schotia brachypetala, Psychotria capensis and Peltophorum africanum, were investigated to assess their anti-aging properties....

  6. Toward a Value for Guided Rafting on Southern Rivers

    Science.gov (United States)

    J. Michael Bowker; Donald B.K. English; Jason A. Donovan

    1996-01-01

    This study examines per trip consumer surplus associated with guided whitewater rafting on two southern rivers. First, household recreation demand functions are estimated based on the individual travel cost model using truncated count data regression methods and alternative price specifications. Findings show mean per trip consumer surplus point estimates between $89...

  7. Organochlorine Pesticide Residues in the Major Rivers of Southern Thailand

    Directory of Open Access Journals (Sweden)

    Abd Naser Haji Samoh

    2009-01-01

    Full Text Available Environmental contaminations by organochlorine pesticides (OCPs of inland water have been a global issue, since most of these compounds are very persistent, bioaccumulative and toxic compounds. Due to the widespread use of DDT for malaria vector eradication programs in the past and no comprehensive works have been conducted to assess trace organic pollutants in river waters, this work is the first effort to assess the contamination levels of OCPs in the major rivers of Southern Thailand. The objectives of this study were to determine the concentration levels of OCPs and oil and grease in the 3 major rivers and to compare the present results with surrounding regions for further assessment of OCPs contamination status in inland waters of Southern Thailand. The water samples were collected along the 3 major rivers (Saiburi, Patani and Tiba River during June 2007-February 2008. Water samples were solid phase extracted with Supelco C-18 cartridge (1g/6 mL and quantified by gas chromatograph (GC-ECD. The concentration of oil and grease was determined by gravimetric method and reported as hexane extractable material (HEM and silica gel treated hexane extractable material (SGT-HEM. Several parameters of waters such as total suspended solid, pH, turbidity, and conductivity were measured. The commonly found OCP residues in these rivers were β-HCH, γ-HCH, heptachlor epoxide, endosulfan 1, p,p’- DDE and endrin aldehyde. The overall results showed that Saiburi River was more polluted with OCPs than Patani and Tiba River, especially p, p’-DDE which was detected in the wide range concentration of 9.6 to 203.1 ng/mL. For oil and grease contamination, Tiba River waters were found to be more polluted than either Patani or Saiburi River. The experimental procedures and analytical results together with the possible sources of OCPs and its environmental impacts are presented.

  8. Southern African Power Pool: Planning and Prospects for Renewable Energy

    Energy Technology Data Exchange (ETDEWEB)

    Miketa, Asami [IRENA, Bonn (Germany); Merven, Bruno [Energy Research Centre, Univ. of Cape Town (South Africa)

    2013-06-25

    With the energy systems of many African countries dominated by fossil-fuel sources that are vulnerable to global price volatility, regional and intra-continental power systems with high shares of renewable energy can provide least-cost option to support continued economic growth and address the continent’s acute energy access problem. Unlocking Africa’s huge renewable energy potential could help to take many people out of poverty, while ensuring the uptake of sustainable technologies for the continent’s long-term development. The report examines the ''renewable scenario'' based on a modelling tool developed by IRENA and tested in cooperation with the South African National Energy Development Institute (SANEDI) and the Southern African Development Community (SADC). Initial results from the System Planning and Test (SPLAT) model show that the share of renewable technologies in Southern Africa could increase from the current 10% to as much as 46% in 2030, with 20% of decentralised capacity coming from renewable sources and nearly 80% of the envisaged capacity additions between 2010 and 2030 being provided by renewable energy technologies. Deployment and export of hydropower from the Democratic Republic of Congo’s Inga hydropower project to the SADC region would significantly reduce average electricity generation costs. Analysis using SPLAT – along with a similar model developed for West Africa – can provide valuable input for regional dialogue and energy projects such as the East and Southern Africa Clean Energy Corridor and the Programme for Infrastructure and Development in Africa (PIDA). IRENA, together with partner organisations, has started plans to set up capacity building and development support for energy system modelling and planning for greater integration of renewables in Africa. IRENA is also completing a similar model and study for East Africa and intends to extend this work to Central and North Africa.

  9. The development of a GIS atlas of southern African freshwater fish ...

    African Journals Online (AJOL)

    The development of a GIS atlas of southern African freshwater fish. LEP Scott, PH Skelton, AJ Booth, L Verheust. Abstract. A geographic information systems (GIS) based atlas of southern African freshwater fish has been developed for the SADC countries. The JLB Smith Institute of Ichthyology, in collaboration with ALCOM, ...

  10. Southern African Phanerozoic Carbonatites: Perspectives on Their Sources and Petrogeneses

    Science.gov (United States)

    Janney, P. E.; Ogungbuyi, P. I.; Marageni, M.; Harris, C.; Reid, D. L.

    2017-12-01

    Found worldwide, carbonatites are particularly numerous in southern Africa and reflect one expression of abundant intraplate alkaline magmatism of Proterozoic to Paleogene age in the region. Phanerozoic southern African carbonatites tend to be concentrated near the margins of the continent (especially the western margin), and near the East African Rift, and often occur in discrete magmatic lineations also containing kimberlites, melilitites, nephelinites and differentiated silica-undersaturated rocks such as phonolites and syenites. We present a synthesis of geochemical and radiogenic and stable isotope results for southern African carbonatites, including new trace element and isotope data from four Phanerozoic carbonatite complexes in South Africa and Namibia: Marinkas Quellen (MQ; southernmost Namibia, ≈525 Ma), Saltpeterkop (SPK; near Sutherland, South Africa, 74 Ma), Zandkopsdrift (ZKD; near Garies, South Africa, 55 Ma, a major REE deposit in development), and Dicker Willem (DW; near Aus, southern Namibia, 49 Ma). All are located in the Early-mid Proterozoic Namaqua-Natal mobile belt. These carbonatite complexes are each associated with linear, NE-SW oriented magmatic provinces, i.e., the Kuboos-Bremen Line of felsic alkaline intrusions and ultramafic lamprophyres (MQ); the Western Cape olivine melilitite province (SPK); the Namaqualand-Bushmanland-Warmbad province of olivine melilitites and kimberlites (ZKD) and the Schwarzeberg-Klinghardt-Gibeon swarm of nephelinites, phonolites and kimberlites (DW), the latter three provinces are of Paleogene to Late Cretaceous age and are clearly age progressive. Each of the four carbonatite complexes contain silica-undersaturated igneous rocks such as potassic trachyte (MQ, SPK & DW), alkaline lamprophyre (ZKD), ijolite (MQ & DW) and olivine melilitite (ZKD and SPK). Most also contain hybrid silicate-carbonate igneous rocks with <35 wt.% SiO2 and ≥20 wt.% CO2 such as nepheline sövite (DW), aillikite (ZKD) and other

  11. Some southern African entry points into global history

    Directory of Open Access Journals (Sweden)

    Neil Parsons

    2009-04-01

    Full Text Available So-called Global History has taken off in the Unites States to liberate undergraduates from Big Power parochialism, and has been the topic of a major conference held in London in May this year. The key element of Global Studies is to demonstrate the connectedness between different peoples and lands and periods of time. This paper is an attempt to crack the small-end of the egg by starting studies in one familiar region of the world, rather than the big-end approach of starting with general explanations or theory and then relating them back to particulars. It suggests three ways in which Southern Africa could be used as the starting point to throw more general light upon the world’s history. First, by taking cues from and asking questions about the latest genetic research which suggests that modern human population dispersal about 60 000 years ago began in Angola-Namibia frontier region. Second, by taking cues and asking questions about Indonesian contact with Africa and coastal settlement that may account for significant influences on southern African societies. Third, by tracing the biographies of real individuals whose careers encompass not only southern Africa but other parts of the world and in doing so demonstrate not only inter- connectedness of cultural, social, political and economic histories but also significant points of comparison in the experience of global trends and events.

  12. Genetics and southern African prehistory: an archaeological view.

    Science.gov (United States)

    Mitchell, Peter

    2010-01-01

    Southern African populations speaking languages that are often - but inaccurately - grouped together under the label 'Khoisan' are an important focus of molecular genetic research, not least in tracking the early stages of human genetic diversification. This paper reviews these studies from an archaeological standpoint, concentrating on modern human origins, the introduction of pastoralism to southern Africa and admixture between the region's indigenous foragers and incoming Bantu-speaking farmers. To minimise confusion and facilitate correlation with anthropological, linguistic and archaeological data it emphasises the need to use ethnolinguistic labels accurately and with due regard for the particular histories of individual groups. It also stresses the geographically and culturally biased nature of the genetic studies undertaken to date, which employ data from only a few 'Khoisan' groups. Specific topics for which the combined deployment of genetic and archaeological methods would be particularly useful include the early history of Ju-Hoan- and Tuu-speaking hunter-gatherers, the expansion of Khoe-speaking populations, the chronology of genetic exchange between hunter-gatherers and farmers, and the origins of the Sotho/Tswana- and Nguni-speaking populations that dominate much of southern Africa today.

  13. River plume patterns and dynamics within the Southern California Bight

    Science.gov (United States)

    Warrick, J.A.; DiGiacomo, P.M.; Weisberg, S.B.; Nezlin, N.P.; Mengel, M.; Jones, B.H.; Ohlmann, J.C.; Washburn, L.; Terrill, E.J.; Farnsworth, K.L.

    2007-01-01

    Stormwater river plumes are important vectors of marine contaminants and pathogens in the Southern California Bight. Here we report the results of a multi-institution investigation of the river plumes across eight major river systems of southern California. We use in situ water samples from multi-day cruises in combination with MODIS satellite remote sensing, buoy meteorological observations, drifters, and HF radar current measurements to evaluate the dispersal patterns and dynamics of the freshwater plumes. River discharge was exceptionally episodic, and the majority of storm discharge occurred in a few hours. The combined plume observing techniques revealed that plumes commonly detach from the coast and turn to the left, which is the opposite direction of Coriolis influence. Although initial offshore velocity of the buoyant plumes was ∼50 cm/s and was influenced by river discharge inertia (i.e., the direct momentum of the river flux) and buoyancy, subsequent advection of the plumes was largely observed in an alongshore direction and dominated by local winds. Due to the multiple day upwelling wind conditions that commonly follow discharge events, plumes were observed to flow from their respective river mouths to down-coast waters at rates of 20–40 km/d. Lastly, we note that suspended-sediment concentration and beam-attenuation were poorly correlated with plume salinity across and within the sampled plumes (mean r2=0.12 and 0.25, respectively), while colored dissolved organic matter (CDOM) fluorescence was well correlated (mean r2=0.56), suggesting that CDOM may serve as a good tracer of the discharged freshwater in subsequent remote sensing and monitoring efforts of plumes.

  14. Africa burning: A thematic analysis of the Southern African Regional Science Initiative (SAFARI 2000)

    Science.gov (United States)

    Swap, Robert J.; Annegarn, Harold J.; Suttles, J. Timothy; King, Michael D.; Platnick, Steven; Privette, Jeffrey L.; Scholes, Robert J.

    2003-07-01

    The Southern African Regional Science Initiative (SAFARI 2000) was a major surface, airborne, and spaceborne field campaign carried out in southern Africa in 2000 and 2001 that addressed a broad range of phenomena related to land-atmosphere interactions and the biogeochemical functioning of the southern African system. This paper presents a thematic analysis and integration of the Journal of Geophysical Research SAFARI 2000 Special Issue, presenting key findings of an intensive field campaign over southern Africa in August and September of 2000. The integrating themes deal with surface emissions characterization; airborne characterizations of aerosols and trace gases; regional haze and trace gas characterization; and radiant measurements by surface, aircraft, and remote sensing platforms. Enhanced regional fuel loads associated with the moist La Niña phase of the El Niño-Southern Oscillation (ENSO) cycle produced above average biomass burning emissions, which consequently dominated all other aerosol and trace gas emissions during the dry season. Southward transport of a broad plume of smoke originating in equatorial Africa and exiting off the east coast toward the Indian Ocean (the river of smoke) is attributed to unusual synoptic airflows associated the ENSO phase. New and revised biogenic and pyrogenic emission factors are reported, including a number of previously unreported oxygenated organic compounds and inorganic compounds from biomass combustion. Emission factors are scaled up to regional emission surfaces for biogenic species utilizing species specific and light-dependent emission factors. Fire scar estimates reveal contradictory information on the timing of the peak and extent of the biomass-burning season. Integrated tall stack coordinated measurements (between ground, airborne and remotely sensing platforms) of upwelling and downwelling radiation in massive thick aerosol layers covering much of southern Africa yield consistent estimates of large

  15. The recreational value of river inflows into South African estuaries ...

    African Journals Online (AJOL)

    For the 37 estimates deemed reliable (but not necessarily valid), the average of the predicted median values of river inflow into estuaries was calculated to be 3.4 c/m3 (South African cents, ZAR) and standard deviation 3.84 c/m3. The average of the predicted mean values was calculated to be 7.4 c/m3 and the standard ...

  16. Aspects of potential climate change impacts on ports and maritime operations around the Southern African coast

    CSIR Research Space (South Africa)

    Rossouw, Marius

    2009-02-01

    Full Text Available to become available, and the resulting somewhat speculative discussions and predictions presented here are uncertain. Some important potential consequences of global warming on the southern African coast are highlighted, and there is presently a clear...

  17. SAFARI 2000 Estimated BVOC Emissions for Southern African Land Cover Types

    Data.gov (United States)

    National Aeronautics and Space Administration — Improved vegetation distribution and emission data for Africa south of the equator were developed for the Southern African Regional Science Initiative (SAFARI 2000)...

  18. Notes on the activity patterns of 12 species of southern African ...

    African Journals Online (AJOL)

    southern African rodents and a new design of activity monitor. M.R. Perrin ... while nocturnal ism in (arboreal) Graphlurus murlnus is believed to . reduce competition with ... It has a wide ap- plication in small mammal behavioural studies. The.

  19. Language Policy and Practice in the Multilingual Southern African Development Community

    Science.gov (United States)

    Mooko, Theophilus

    2009-01-01

    This study explores the language policy and practice of the Southern African Development Community (SADC), an African regional economic organisation made up of 14 member states (Angola, Botswana, Democratic Republic of Congo, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namibia, South Africa, Swaziland, United Republic of Tanzania, Zambia…

  20. Flow-gauging structures in South African rivers Part 1: An overview ...

    African Journals Online (AJOL)

    provided on the different structures will assist the reader with the selection of an appropriate structure. The historical development of the gauging structure network in South African rivers is briefly discussed. Gauging structures used in South African rivers and basic design criteria for the preferred structures at this stage, ...

  1. 21st Century African Philosophy of Adult and Human Resource Education in Southern Africa

    Science.gov (United States)

    Mutamba, Charlene

    2012-01-01

    This paper will attempt to define a philosophy of adult education for the purpose of workforce development in Southern Africa. The different influences such as Ubuntu and communalism, indigenous education, diversity western philosophy, globalization and technology are explored in the context of the Southern African region.

  2. Threatened southern African soils: A need for appropriate ecotoxicological risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Eijsackers, Herman [Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Reinecke, Adriaan; Reinecke, Sophie [Department of Botany & Zoology, Stellenbosch University, Private Bag X1, Matieland 7602 (South Africa); Maboeta, Mark, E-mail: mark.maboeta@nwu.ac.za [Unit for Environmental Sciences and Management, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa)

    2017-03-15

    In southern Africa arable soils are limited due to low rainfall and are threatened by anthropogenic activities like agriculture and mining making it susceptible to degradation. The aim of this study is to review the existing information available with regards to soil contamination and its possible threats towards biodiversity and quality of southern African soils. Some of the issues being addressed in this paper include the focus areas of ecotoxicological research in southern African countries, levels of contaminants in soils, the impacts of climate on soil animals and the representativity of standardised test species. In order to address this, we report on a literature search, which was done to determine the main focus areas of soil ecotoxicological research, highlighting strengths and research needs in comparison to approaches elsewhere in the world. Further, to address if the risk assessment approaches of Europe and the USA are valid for southern African environmental conditions; this in the light of differences in temperature, rainfall and fauna. It is concluded that risk assessment procedures for Europe and the USA were based on non-southern African conditions making it necessary to rethink risk assessment studies; although limited, in southern Africa. We recommend future research that has to be undertaken to address these issues. This research should include investigating species sensitivities in responses to contamination and including insects likes ants and termites in ecological risk assessment studies.

  3. Threatened southern African soils: A need for appropriate ecotoxicological risk assessment

    International Nuclear Information System (INIS)

    Eijsackers, Herman; Reinecke, Adriaan; Reinecke, Sophie; Maboeta, Mark

    2017-01-01

    In southern Africa arable soils are limited due to low rainfall and are threatened by anthropogenic activities like agriculture and mining making it susceptible to degradation. The aim of this study is to review the existing information available with regards to soil contamination and its possible threats towards biodiversity and quality of southern African soils. Some of the issues being addressed in this paper include the focus areas of ecotoxicological research in southern African countries, levels of contaminants in soils, the impacts of climate on soil animals and the representativity of standardised test species. In order to address this, we report on a literature search, which was done to determine the main focus areas of soil ecotoxicological research, highlighting strengths and research needs in comparison to approaches elsewhere in the world. Further, to address if the risk assessment approaches of Europe and the USA are valid for southern African environmental conditions; this in the light of differences in temperature, rainfall and fauna. It is concluded that risk assessment procedures for Europe and the USA were based on non-southern African conditions making it necessary to rethink risk assessment studies; although limited, in southern Africa. We recommend future research that has to be undertaken to address these issues. This research should include investigating species sensitivities in responses to contamination and including insects likes ants and termites in ecological risk assessment studies.

  4. Strategic culture of the Southern African Development Community ...

    African Journals Online (AJOL)

    (SADC) Brigade took pride of place at the opening of the 2007 SADC Summit in Lusaka, Zambia. This SADC Brigade is tied in closely to both the security architecture of the African Standby Force (ASF) of the African Union (AU) and the SADC Mutual Defence Pact. In the recent past (1998), military interventions by SADC ...

  5. Peace parks in Southern Africa: bringers of an African renaissance

    NARCIS (Netherlands)

    Buscher, B.E.; van Amerom, M.

    2005-01-01

    The pursuit of an African Renaissance has become an important aspect of regional cooperation between South Africa and its neighbours. Transfrontier conservation areas, or 'Peace Parks' as they are popularly called, have been identified as key instruments to promote the African Renaissance dream, and

  6. Peace parks in Southern Africa: bringers of an African Renaissance?

    NARCIS (Netherlands)

    H.C. Buscher

    2005-01-01

    textabstractThe pursuit of an African Renaissance has become an important aspect of regional cooperation between South Africa and its neighbours. Transfrontier conservation areas, or ‘Peace Parks’ as they are popularly called, have been identified as key instruments to promote the African

  7. Reconsidering the origins of the Southern African regionalism thirty years later: towards a constructivist approach to the origins of SADC

    Directory of Open Access Journals (Sweden)

    José Abel Moma

    2012-01-01

    Full Text Available The creation of SADCC has generated a debate over the real origins of the southern African model of regionalism. This paper develops the idea that the origins of SADC are both internal and external. Thus, southern African regionalism is understood as a constructivist articulation of internal and external inputs, which determined the creation of SADCC and its transformation into SADC.

  8. Approaching Southern Theory: Explorations of Gender in South African Education

    Science.gov (United States)

    Epstein, Debbie; Morrell, Robert

    2012-01-01

    This article draws on the five other papers from South Africa in this issue of "Gender and Education" to consider how Southern theory has been developed and is developing in relation to gender and education in South Africa. We argue that Southern theory is not an on-the-shelf solution to global geopolitical inequalities but a work in…

  9. Southern African Linguistics and Applied Language Studies - Vol 31 ...

    African Journals Online (AJOL)

    Exploring a conceptual space for studying translation and development · EMAIL FULL TEXT EMAIL FULL TEXT ... The translator status, the translation market and developing economies: A preliminary study of ... AJOL African Journals Online.

  10. Southern African Journal of Anaesthesia and Analgesia - Vol 19, No ...

    African Journals Online (AJOL)

    Pioneers in South African Anaesthesia: Professor Arthur Bull and the Taurus Radiofrequency Blood Warmer · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. PC Gordon, ND Hauser, J Marais, 194-196 ...

  11. Southern African Business Review - Vol 13, No 2 (2009)

    African Journals Online (AJOL)

    The availability and use of competitive and business intelligence in South African business organisations · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. P Venter, D Tustin ...

  12. Southern African Business Review - Vol 19, No 1 (2015)

    African Journals Online (AJOL)

    The relationship between South African CEO compensation and company performance in the banking industry · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. B Deysel, J Kruger, 137-169 ...

  13. Southern African Business Review - Vol 15, No 1 (2011)

    African Journals Online (AJOL)

    Supply chain management problems at South African automotive component manufacturers · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. MJ Naude, JA Badenhorst-Weiss ...

  14. Southern African Business Review - Vol 17, No 2 (2013)

    African Journals Online (AJOL)

    Boards and governance in African national cricket organisations: An exploratory ... and key success factors of wine tourism · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT ... Psychological career meta-capacities in relation to employees' ...

  15. A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

    Directory of Open Access Journals (Sweden)

    Emile R Chimusa

    2015-03-01

    Full Text Available We report a study of genome-wide, dense SNP (∼ 900K and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region.

  16. A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

    Science.gov (United States)

    Chimusa, Emile R; Meintjies, Ayton; Tchanga, Milaine; Mulder, Nicola; Seoighe, Cathal; Seioghe, Cathal; Soodyall, Himla; Ramesar, Rajkumar

    2015-03-01

    We report a study of genome-wide, dense SNP (∼ 900K) and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region.

  17. Ohio River backwater flood-inundation maps for the Saline and Wabash Rivers in southern Illinois

    Science.gov (United States)

    Murphy, Elizabeth A.; Sharpe, Jennifer B.; Soong, David T.

    2012-01-01

    Digital flood-inundation maps for the Saline and Wabash Rivers referenced to elevations on the Ohio River in southern Illinois were created by the U.S. Geological Survey (USGS). The inundation maps, accessible through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent of flooding corresponding to selected water levels (gage heights) at the USGS streamgage at Ohio River at Old Shawneetown, Illinois-Kentucky (station number 03381700). Current gage height and flow conditions at this USGS streamgage may be obtained on the Internet at http://waterdata.usgs.gov/usa/nwis/uv?03381700. In addition, this streamgage is incorporated into the Advanced Hydrologic Prediction Service (AHPS) flood warning system (http://water.weather.gov/ahps/) by the National Weather Service (NWS). The NWS forecasts flood hydrographs at many places that are often co-located at USGS streamgages. That NWS forecasted peak-stage information, also shown on the Ohio River at Old Shawneetown inundation Web site, may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, eight water-surface elevations were mapped at 5-foot (ft) intervals referenced to the streamgage datum ranging from just above the NWS Action Stage (31 ft) to above the maximum historical gage height (66 ft). The elevations of the water surfaces were compared to a Digital Elevation Model (DEM) by using a Geographic Information System (GIS) in order to delineate the area flooded at each water level. These maps, along with information on the Internet regarding current gage heights from USGS streamgages and forecasted stream stages from the NWS, provide emergency management personnel and residents with information that is critical for flood response activities such as evacuations and road closures, as well as for post-flood recovery efforts.

  18. External controls on Quaternary fluvial incision and terrace formation at the Segre River, Southern Pyrenees

    NARCIS (Netherlands)

    Stange, K.M.; van Balen, R.T.; Vandenberghe, J.; Peña, J.L.; Sancho, C.

    2013-01-01

    Focusing on climatic- and structural (tectonic) controls, we aim to determine their relative importance for the (Pliocene to Quaternary) fluvial landscape evolution in the Southern Pyrenees foreland. We investigate the Segre River, which is one of the major streams of the Southern Pyrenees that

  19. HIV/TB: When is it safe to start HAART? | Wood | Southern African ...

    African Journals Online (AJOL)

    Southern African Journal of HIV Medicine. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 9, No 4 (2008) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected ...

  20. Electricity supply and demand scenarios for the Southern African power pool

    CSIR Research Space (South Africa)

    Spalding-Fecher, R

    2017-02-01

    Full Text Available The study presents long-term electricity supply and demand scenarios for the twelve countries in the Southern African Power Pool, based on detailed bottom-up demand analysis for all countries and a set of internally consistent development scenarios...

  1. Review of Southern African Studies - Vol 12, No 1-2 (2008)

    African Journals Online (AJOL)

    History of Electricity in Lesotho and The Place of 'Muela Hydropower Plant in The Wider Context of The Southern African Power Pool · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. T Tsikoane. http://dx.doi.org/10.4314/rosas.v12i1-2.53640 ...

  2. Report on the establishment of the Southern African Student Affairs ...

    African Journals Online (AJOL)

    The formation of a South African federation was proposed in September 2007 by Ms. Naledi Pandor, then South ... SAFSAS hopes to strengthen collaboration between stakeholders within the higher education and ... SAS agenda, such as higher education transformation, models structures and strategies in. SAS, knowledge ...

  3. Extra-territorial African police and soldiers in Southern Rhodesia ...

    African Journals Online (AJOL)

    Scientia Militaria: South African Journal of Military Studies. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 38, No 1 (2010) >. Log in or Register to get access to full text downloads.

  4. The child in the outdoor classroom | Oberholzer | Southern African ...

    African Journals Online (AJOL)

    This work is licensed under a Creative Commons Attribution 3.0 License. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL · News. OTHER RESOURCES... for Researchers · for ...

  5. Southern African Journal of Anaesthesia and Analgesia - Vol 24, No ...

    African Journals Online (AJOL)

    An evaluation of personality traits associated with job satisfaction among South African anaesthetists using the Big Five Inventory · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. P Kisten, H Kluyts, 9-15 ...

  6. Happy Acres educational field centre | Cauldwell | Southern African ...

    African Journals Online (AJOL)

    This work is licensed under a Creative Commons Attribution 3.0 License. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL · News. OTHER RESOURCES... for Researchers · for ...

  7. Antiretroviral drug resistance: A guide for the southern African clinician

    African Journals Online (AJOL)

    Both private and public sector see a bewildering clinical array of patients taking failing antiretroviral (ARV) regimens. We intend this article to provide a practical guide to help clinicians understand and manage ARV drug resistance in an African context. ARV resistance is a rapidly evolving field, requiring expertise in dealing ...

  8. Southern African Linguistics and Applied Language Studies - Vol 30 ...

    African Journals Online (AJOL)

    ʼn Forensies-semantiese beskouing van die woordgebruik 'onkoste' in die hofsaak Commissioner for South African Revenue Service vs. Labat Africa Limited · EMAIL ... Applying Google Translate in a higher education environment: Translation products assessed · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL ...

  9. Southern African Linguistics and Applied Language Studies - Vol 30 ...

    African Journals Online (AJOL)

    Enablers and barriers to multilingualism in South African university classrooms · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD ... Exposure to audiovisual programs as sources of authentic language input and second language acquisition in informal settings · EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD ...

  10. SAFERE: Southern African Feminist Review - Vol 3, No 1 (1999)

    African Journals Online (AJOL)

    Feminism and Masculinity in an African Capitalist Context: · EMAIL FULL TEXT EMAIL FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Mwenda G. Ntarangwi, 19-32. http://dx.doi.org/10.4314/safere.v3i1.23948 ...

  11. A woman Leading | Matshe | SAFERE: Southern African Feminist ...

    African Journals Online (AJOL)

    -65. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

  12. Southern Coup: Recruiting African American Faculty Members at an Elite Private Southern Research University

    Science.gov (United States)

    Barrett, Thomas Gregory; Smith, Theophus

    2008-01-01

    Competition for highly qualified African American faculty members among elite universities in the United States remains keen. Two of the most successful research universities at recruiting African American faculty members are located in the Southeast. Employing a conceptual framework grounded in organizational culture and climate literature, in…

  13. Life history and diet of two southern African smoothhound sharks ...

    African Journals Online (AJOL)

    Mustelus mustelus and M. palumbes) off southern Africa are described and compared. Free-swimming male M. mustelus measured 390–1 450 mm total length (TL), whereas females were recorded up to 1 650 mm TL. Most specimens of both ...

  14. Identity and distribution of southern African sciaenid fish species of ...

    African Journals Online (AJOL)

    Two Umbrina species, U. canariensis Valenciennes 1843 and U. robinsoni Gilchrist and Thompson 1908, are recognised from southern Africa. The latter species was hitherto believed to be a synonym of Umbrina ronchus Valenciennes 1843 (type locality Canary Islands). U. canariensis is distributed along the South Africa ...

  15. Health evaluation of African penguins (Spheniscus demersus in southern Africa

    Directory of Open Access Journals (Sweden)

    Nola J. Parsons

    2016-09-01

    Full Text Available The African penguin (Spheniscus demersus is an endangered seabird that breeds along the coast of Namibia and South Africa, and disease surveillance was identified as a priority for its conservation. Aiming for the establishment of baseline data on the presence of potential pathogens in this species, a comprehensive health assessment (blood smear examination, haematology, biochemistry and serology was conducted on samples obtained from 578 African penguins at 11 breeding colonies and a rehabilitation centre. There were 68 penguins that were seropositive for at least one of seven pathogens tested: avian encephalomyelitis virus, avian infectious bronchitis virus, avian reovirus, infectious bursal disease virus, Newcastle disease virus, Mycoplasma gallisepticum and Mycoplasma synoviae. All samples were seronegative for avian influenza virus subtypes H5 and H7 and infectious laryngotracheitis virus. The apparent prevalence of Babesia sp. and Borrelia sp. in blood smears was consistent with previous studies. Babesia-infected individuals had a regenerative response of the erythrocytic lineage, an active inflammatory response and hepatic function impairment. These findings indicate that African penguins may be exposed to conservation-significant pathogens in the wild and encourage further studies aiming for the direct detection and/or isolation of these microorganisms.

  16. The Southern African Regional Science Initiative (SAFARI 2000). Dry-Season Campaign: An Overview

    Science.gov (United States)

    Swap, R. J.; Annegarn, H. J.; Suttles, J. T.; Haywood, J.; Hely, C.; Hobbs, P. V.; Holben, B. N.; Ji, J.; King, M. D.; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The Southern African Regional Science Initiative (SAFARI 2000) is an international science project investigating the southern African earth-atmosphere-human system. The experiment was conducted over a two-year period March 1999 - March 2001. The dry season field campaign (August-Steptember 2000) was the most intensive activity and involving over 200 scientists from 18 different nations. The main objectives of this campaign were to characterize and quantify the biogenic, pyrogenic and anthropogenic aerosol and trace gas emissions and their transport and transformations in the atmosphere and to validate the NASA Earth Observing System (EOS) satellite Terra within a scientific context. Five aircraft, namely two South African Weather Service aircraft, University of Washington CV-580, the UK Meteorological Office C-130 and the NASA ER-2, with different altitude capabilities, participated in the campaign. Additional airborne sampling of southern African air masses that had moved downwind of the subcontinent was conducted by the CSIRO over Australia. Multiple observations were taken in various sectors for a variety of synoptic conditions. Flight missions were designed to maximize synchronous over-flights of the NASA TERRA satellite platform, above regional ground validation and science targets. Numerous smaller-scale ground validation activities took place throughout the region during the campaign period.

  17. Atmospheric River Development and Effects on Southern California

    Science.gov (United States)

    Harris, S. M.; Carvalho, L. V.

    2014-12-01

    Throughout most of southern California (SCA) annual precipitation totals occur from relatively few storms per season. Any changes to storm frequency or intensity may dramatically impact the region, as its landscapes are prone to various rainfall-induced hazards including landslides and floods. These hazards become more frequent following drought or fire events, conditions also reliant on precipitation and common in SCA. Rainfall forecasts are especially difficult to determine as regional precipitation is affected by numerous phenomena. On synoptic timescales, atmospheric rivers (ARs) are one such phenomenon known to impact SCA rainfall. ARs are channels of high water vapor content found within the lower atmosphere that transport moisture towards midlatitudes. In areas with varying topography, ARs often produce high-intensity precipitation due to orographic forcing. Although much insight has been gained in understanding AR climatology affecting North America's western coast, the spatiotemporal characteristics and atmospheric forcings driving ARs to SCA need to be further addressed. The goal of this work is to understand the characteristics of ARs that impact SCA and to distinguish them from ARs that impact northern latitudes. We investigate AR characteristics as well as atmospheric features prior to plume initiation for ARs impacting different landfall regions along North America's western coast between 1998-2008. Dates of AR events are organized according to landfall region using total precipitable water (TPW) fields from the National Oceanic and Atmospheric Administration's Climate Forecast System Reanalysis (CFSR). Additional CFSR fields are used to create anomaly composites of moist static energy, geopotential height, as well as upper-level zonal and low-level meridional winds for each landfall region on the day of and prior to AR occurrence. ARs that impact SCA display different TPW plume characteristics as well as wave train patterns throughout the AR

  18. Microstructure-mediated Optical Effects in Southern African Snakes

    Directory of Open Access Journals (Sweden)

    Singh Ishan

    2017-01-01

    Full Text Available The scales of the African Viper Bitis arietans were tested for optical effects. Spectral intensity was recorded at incident angles over the visible spectrum for dark, pale, and ventral scale regions. The lowest spectral intensity recordings were associated with scales which have the greatest level of micro-structuring. Our results indicate that scale appearance in B. arietans is a product of microstructure-mediated optical effects. The optical effect may play a role in improving the ecological performance of the snake in its natural environment.

  19. Mitochondrial DNA analysis of two southern African elephant populations

    Directory of Open Access Journals (Sweden)

    M.F. Essop

    1996-08-01

    Full Text Available The modern view is that there are at most only two valid forms of the African elephant namely Loxodonta qfricana africana, the bush elephant, and L.a. cyclotis, the forest elephant (Ansell 1974; Meester et al. 1986. The Knysna elephant which was also described as a separate sub-species is now almost extinct. Plans to augment the remnant population by introducing other animals must take into account the taxonomic questions and issue of conserving elephant gene pools (Greig 1982a. Mitochondrial DNA (mtDNA restriction fragment-size comparisons were performed on specimens from the Kruger National Park and the Addo Elephant National Park. If the Addo population's results are extrapolated to the Knysna population, it may be concluded that there is no genetic evidence for the Kruger and Knysna elephant populations to be considered as different sub-species.

  20. The Southern African Regional Science Initiative (SAFARI 2000): Overview of the Dry Season Field Campaign

    Science.gov (United States)

    Swap, R. J.; Annegarn, H. J.; Suttles, J. T.; Haywood, J.; Helmlinger, M. C.; Hely, C.; Hobbs, P. V.; Holben, B. N.; Ji, J.; King, M. D.

    2002-01-01

    The Southern African Regional Science Initiative (SAFARI 2000) is an international project investigating the earth atmosphere -human system in southern Africa. The programme was conducted over a two year period from March 1999 to March 2001. The dry season field campaign (August-September 2000) was the most intensive activity involved over 200 scientist from eighteen countries. The main objectives were to characterize and quantify biogenic, pyrogenic and anthropogenic aerosol and trace gas emissions and their transport and transformations in the atmosphere and to validate NASA's Earth Observing System's Satellite Terra within a scientific context. Five aircraft-- two South African Weather Service Aeorcommanders, the University of Washington's CV-880, the U.K. Meteorological Office's C-130, and NASA's ER-2 --with different altitude capabilities, participated in the campaign. Additional airborne sampling of southern African air masses, that had moved downwind of the subcontinent, was conducted by the CSIRO over Australia. Multiple Observations were made in various geographical sections under different synoptic conditions. Airborne missions were designed to optimize the value of synchronous over-flights of the Terra Satellite platform, above regional ground validation and science targets. Numerous smaller scale ground validation activities took place throughout the subcontinent during the campaign period.

  1. An Investigation of the Migration of Africanized Honey Bees into the Southern United States

    Science.gov (United States)

    Navarro, Hector

    1997-01-01

    It is estimated that Apis mellifera scutellata, a honey bee subspecies from Africa, now extends over a 20 million square kilometer range that includes much of South America and practically all of Central America, and recently has been introduced to the southern United States. African honeybees were introduced into Brazil in 1956 by a Brazilian geneticist, Mr. Warwick Kerr. At the insistence of the Brazilian Ministry of Agriculture, in 1957, 26 colonies were accidentally released in a eucalyptus forest outside S5o Paulo. The swelling front of the bees was recorded as traveling between 80 and 500 kilometers a year. David Roubik, one of the original killer bee team members estimated that there were one trillion individual Africanized/African honey bees in Latin America. An estimate that is thought to be conservative.

  2. Anthropogenic radiative forcing of southern African and Southern Hemisphere climate variability and change

    CSIR Research Space (South Africa)

    Engelbrecht, FA

    2014-10-01

    Full Text Available of stratospheric ozone, greenhouse gasses, aerosols and sulphur dioxide, can improve the model's skill to simulate inter-annual variability over southern Africa. The paper secondly explores the role of different radiative forcings of future climate change over...

  3. Hunter-gatherer genomic diversity suggests a southern African origin for modern humans.

    Science.gov (United States)

    Henn, Brenna M; Gignoux, Christopher R; Jobin, Matthew; Granka, Julie M; Macpherson, J M; Kidd, Jeffrey M; Rodríguez-Botigué, Laura; Ramachandran, Sohini; Hon, Lawrence; Brisbin, Abra; Lin, Alice A; Underhill, Peter A; Comas, David; Kidd, Kenneth K; Norman, Paul J; Parham, Peter; Bustamante, Carlos D; Mountain, Joanna L; Feldman, Marcus W

    2011-03-29

    Africa is inferred to be the continent of origin for all modern human populations, but the details of human prehistory and evolution in Africa remain largely obscure owing to the complex histories of hundreds of distinct populations. We present data for more than 580,000 SNPs for several hunter-gatherer populations: the Hadza and Sandawe of Tanzania, and the ≠Khomani Bushmen of South Africa, including speakers of the nearly extinct N|u language. We find that African hunter-gatherer populations today remain highly differentiated, encompassing major components of variation that are not found in other African populations. Hunter-gatherer populations also tend to have the lowest levels of genome-wide linkage disequilibrium among 27 African populations. We analyzed geographic patterns of linkage disequilibrium and population differentiation, as measured by F(ST), in Africa. The observed patterns are consistent with an origin of modern humans in southern Africa rather than eastern Africa, as is generally assumed. Additionally, genetic variation in African hunter-gatherer populations has been significantly affected by interaction with farmers and herders over the past 5,000 y, through both severe population bottlenecks and sex-biased migration. However, African hunter-gatherer populations continue to maintain the highest levels of genetic diversity in the world.

  4. Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil

    Directory of Open Access Journals (Sweden)

    Thais Collet

    2009-01-01

    Full Text Available As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European.

  5. Genetic structure of drone congregation areas of Africanized honeybees in southern Brazil.

    Science.gov (United States)

    Collet, Thais; Cristino, Alexandre Santos; Quiroga, Carlos Fernando Prada; Soares, Ademilson Espencer Egea; Del Lama, Marco Antônio

    2009-10-01

    As yet, certain aspects of the Africanization process are not well understood, for example, the reproductive behavior of African and European honeybees and how the first Africanized swarms were formed and spread. Drone congregation areas (DCAs) are the ideal place to study honeybee reproduction under natural conditions since hundreds of drones from various colonies gather together in the same geographical area for mating. In the present study, we assessed the genetic structure of seven drone congregations and four commercial European-derived and Africanized apiaries in southern Brazil, employing seven microsatellite loci for this purpose. We also estimated the number of mother-colonies that drones of a specific DCA originated from. Pairwise comparison failed to reveal any population sub-structuring among the DCAs, thus indicating low mutual genetic differentiation. We also observed high genetic similarity between colonies of commercial apiaries and DCAs, besides a slight contribution from a European-derived apiary to a DCA formed nearby. Africanized DCAs seem to have a somewhat different genetic structure when compared to the European.

  6. High-sodium food choices by southern, urban African Americans with heart failure.

    Science.gov (United States)

    Kollipara, Usha K; Mo, Vivian; Toto, Kathleen H; Nelson, Lauren L; Schneider, Ruth A; Neily, Jennifer B; Drazner, Mark H

    2006-03-01

    Sodium restriction is important in the management of heart failure (HF). Although many low-sodium educational resources are available, few are directed specifically at urban African Americans. A registered dietitian prospectively interviewed 50 African-American and 25 white patients in an urban public hospital (derivation cohort) in Dallas, TX, using a food-frequency instrument that listed 146 food choices. Foods >300 mg sodium/serving consumed at least weekly by 50% of an ethnic group were classified as being a high-sodium core food for that group. Classification of foods (core or not core) was validated in a second African-American cohort (n = 144). Five high-sodium food choices were classified as core food in both the derivation and validation African-American cohorts (salt in cooking, canned vegetables, cheese, processed meats, and cold cereal) and another 3 when the derivation and validation cohorts were combined (fast food, fried chicken, and corn bread). Four of these 8 foods were not classified as core foods in whites. Eight high-sodium foods were frequently consumed by southern, urban African Americans with heart failure. Several of these foods were not commonly consumed by whites, emphasizing the need to be sensitive to ethnic differences in dietary habits when educating patients about sodium intake.

  7. Water quality index for Al-Gharraf River, southern Iraq

    Directory of Open Access Journals (Sweden)

    Salam Hussein Ewaid

    2017-06-01

    Full Text Available The Water Quality Index has been developed mathematically to evaluate the water quality of Al-Gharraf River, the main branch of the Tigris River in the south of Iraq. Water samples were collected monthly from five sampling stations during 2015–2016, and 11 parameters were analyzed: biological oxygen demand, total dissolved solids, the concentration of hydrogen ions, dissolved oxygen, turbidity, phosphates, nitrates, chlorides, as well as turbidity, total hardness, electrical conductivity and alkalinity. The index classified the river water, without including turbidity as a parameter, as good for drinking at the first station, poor at stations 2, 3, 4 and very poor at station 5. When turbidity was included, the index classified the river water as unsuitable for drinking purposes in the entire river. The study highlights the importance of applying the water quality indices which indicate the total effect of the ecological factors on surface water quality and which give a simple interpretation of the monitoring data to help local people in improving water quality.

  8. The coherent variability of African river flows : composite climate ...

    African Journals Online (AJOL)

    The composite structure of the ocean and atmosphere around Africa is studied in the context of river flow variability. Annual streamflows are analysed for the Blue and White Nile, Congo, Niger, Senegal, Zambezi, and Orange Rivers, and inflow to Lake Malawi. Spectral energy is concentrated in 6.6- and 2.4-year bands.

  9. Metal surveys in South African estuaries I. Swartkops River

    International Nuclear Information System (INIS)

    Watling, R.J.; Watling, H.R.

    1982-01-01

    Water, surface sediment and sediment core samples were collected from sites in the Swartkops River up to 15 km from the mouth and analysed for up to sixteen elements. The results indicate the presence of four main areas of contamination in the river, at Redhouse, Swartkops, the brickworks and Amsterdam Hoek. The accumulation of zinc, copper, lead and nickel by oysters grown at the mouth of the river confirms the presence of greater than normal metal concentrations in the river. Fish-water Flats outfall contributes metals to the nearshore marine environment, but the strong tidal sweep disperses the effluent relatively quickly so that metal build-up in the area is minimal. In general, metal levels in the Swartkops River are low and, as yet, the area cannot be described as 'polluted' in the true sense of the word

  10. Circulation controls on southern African precipitation in coupled models: The role of the Angola Low

    Science.gov (United States)

    Munday, Callum; Washington, Richard

    2017-01-01

    In southern Africa, models from the latest Coupled Model Intercomparison Project produce a wide variety of rainfall climatologies. Differences between models in rainfall amount reach 70% in the rainy season (December-February; DJF), and the median model overestimates rainfall by between 15 and 40% throughout the annual cycle. This paper investigates the role of an understudied regional circulation feature, the Angola Low, in differentiating between model estimates of precipitation. In austral spring, the Angola Low is a heat low, driven by strong surface heating whereas in DJF it is more similar to a tropical low and is associated with moist instability. In the austral summer, we find that the simulated strength of the Angola Low is associated with between 40 and 60% of the intermodel variability in model mean rainfall across the subcontinent. The relationship is particularly strong along a northwest, southeast axis aligned from Angola down to the Mozambican Channel. Along this axis, models with stronger Angola Lows simulate enhanced, by up to 50 g kg-1 ms-1, northeasterly and northwesterly moisture transport. The enhanced southward moisture flux in models with relatively deep Angola Lows increases the rate of moisture convergence in central areas of the subcontinent and reduces moisture divergence across the Mozambican coast. The results highlight the need to better understand the links between the Angola Low and southern African rainfall and suggest that improving the simulation of the Angola Low can help to constrain model estimates of southern African rainfall.

  11. Tracking the movements of a post-nesting Southern River Terrapin (Batagur affinis edwardmolli)

    Science.gov (United States)

    Chen, Pelf-Nyok; Wong, Adrian

    2015-09-01

    A Southern River Terrapin (Batagur affinis edwardmolli) Conservation Project was initiated on one terrapin nesting bank in 2011, following the discovery of a River Terrapin population in the Kemaman River, Terengganu in 2010. Since this project was initiated, Turtle Conservation Society of Malaysia (TCS) was instrumental in the gazettement of three nesting banks along the Kemaman River, from which all River Terrapin eggs are collected for incubation. However, there are at least a dozen other "unprotected" nesting banks along the river, where all eggs were collected for human consumption. This project attempted to determine the movements of a post-nesting River Terrapin, with hopes that it would provide the preliminary baseline information on the utilization of adjacent nesting banks. The solution was a GPS tracking device that transmitted coordinates every hour over cellular networks. Location-based data was sent via Short Message Service (SMS) to our own SMS gateway running on a Raspberry Pi credit-card size computer, which was then logged in a database and presented graphically via Google Maps. It was a complete tracking and monitoring system. This solution enabled researchers to remotely track the movements of a River Terrapin, hence reducing the costs of research. The movements of a post-nesting River Terrapin were tracked for eight days before the battery was drained. On the third day, this River Terrapin ascended an adjacent riverbank and spent less than an hour on the bank, presumably to deposit her remaining eggs. This study confirmed that River Terrapins do utilize other suitable nesting banks if/whenever available. Results from such tracking studies will be used to leverage on the protection of adjacent nesting banks, thus providing greater protection for the critically endangered River Terrapins.

  12. Biodegradation of hexadecane using sediments from rivers and lagoons of the Southern Gulf of Mexico.

    Science.gov (United States)

    García-Cruz, N Ulises; Sánchez-Avila, Juan I; Valdés-Lozano, David; Gold-Bouchot, Gerardo; Aguirre-Macedo, Leopoldina

    2018-03-01

    The Southern Gulf of Mexico is an area highly impacted by crude oil extraction, refining activities and the presence of natural petroleum seepage. Oceanic currents in the Gulf of Mexico continually facilitate the transport of hydrocarbons to lagoons and rivers. This research evaluated hexadecane (HXD) degradation in marine sediment samples from lagoons and rivers that are fed by the Southern Gulf of Mexico, specifically six samples from rivers, three samples from lagoons, and one sample from a marine outfall. The highest rates of biodegradation were observed in sediments from the mouths of the Gonzalez River and the Champotón Lagoon. The lowest consumption rate was found in sediment from the mouth of the Coatzacoalcos River. With regards to the Ostión Lagoon and the Grijalva River, there was a low rate of consumption, but a high efficiency of degradation which took place at the end of the experiments. No correlation was found between the consumption rate and the environmental physicochemical parameters. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. A southern African origin and cryptic structure in the highly mobile plains zebra

    DEFF Research Database (Denmark)

    Pedersen, Casper-Emil T; Albrechtsen, Anders; Etter, Paul D.

    2018-01-01

    insights into the past phylogeography of the species. The results identify a southern African location as the most likely source region from which all extant populations expanded around 370,000 years ago. We show evidence for inclusion of the extinct and phenotypically divergent quagga (Equus quagga quagga......The plains zebra (Equus quagga) is an ecologically important species of the African savannah. It is also one of the most numerous and widely distributed ungulates, and six subspecies have been described based on morphological variation. However, the within-species evolutionary processes have been...... difficult to resolve due to its high mobility and a lack of consensus regarding the population structure. We obtained genome-wide DNA polymorphism data from more than 167,000 loci for 59 plains zebras from across the species range, encompassing all recognized extant subspecies, as well as three mountain...

  14. Diversity as a common research priority for Nordic and Southern African Universities

    DEFF Research Database (Denmark)

    Petersen, Karen Bjerg

    This paper sets out to consider concepts of diversity as means to discuss and address the increasing diversity of modern societies and to reflect the development of research priorities for universities in Nordic and Southern African countries. Based on reconceptualisations of theoretical concepts...... like culture, multiculturalism and national identity the presentation will address and reflect upon how modern societies in South and North are becoming increasingly diverse with respect to demographic and ethno cultural composition of the population. The paper sets out to discuss how various European...... countries like e.g. Denmark have responded differently to diversification during the past decades. Based on this, challenges in deal-ing with diversity as a common research priority for Nordic and African universities will be shortly addressed....

  15. Water pollution and cyanobacteria's variation of rivers surrounding southern Taihu Lake, China.

    Science.gov (United States)

    Sun, Mingyang; Huang, Linglin; Tan, Lisha; Yang, Zhe; Baig, Shams Ali; Sheng, Tiantian; Zhu, Hong; Xu, Xinhua

    2013-05-01

    The water quality and cyanobacterial variation of rivers surrounding southern Taihu Lake, China were purposively monitored from 2008 to 2010. Trophic level index (TLI) was used to evaluate the trophic levels of southern Taihu Lake. Results showed a considerable decline in the monitored data compared with 2007, and the data showed downward trends year after year. The TLI decreased from 55.6 to 51.3, which implied that southern Taihu Lake was mildly eutrophic. The water quality and cyanobacterial variation indicated a positive response to the adopted control measures in the southern Taihu Lake basin, but the intra- and inter-annual variability was still quite varied. High concentrations of nitrogen and phosphorus typically lead to algae outbreaks, however, the cyanobacteria growth may result in a decline of the concentration of nitrogen and phosphorus. Temperature and other weather conditions are also important factors for algae outbreaks; the risk of blue-green algal blooms still persists.

  16. Seismic signatures of the Pan-African orogeny: implications for southern Indian high-grade terranes

    Science.gov (United States)

    Rai, Abhishek; Gaur, V. K.; Rai, S. S.; Priestley, K.

    2009-02-01

    We present the results of a study designed to investigate and compare the seismic characteristics of the once contiguous terranes of eastern Gondwanaland, now incorporated in five separated continental masses, which, during the Neoproterozoic (~600Ma) Pan-African orogeny, suffered a high degree of thermal stress and deformation. Receiver functions and surface wave data from stations located in East Antarctica, Sri Lanka, the southern-Indian high-grade terranes, Madagascar and the Tanzania-Mozambique belt, were used to determine the shear-wave velocity structure, Moho depth and VP/VS values of the respective crustal segments. This study provides an additional dimension to the otherwise well-documented characteristic petrology of their surface exposures and other geological signatures such as their extensive granulitization and gem formation during the Pan-African event. Analysis of the receiver functions and surface wave data for these seismic stations located on their present day widely distributed continental fragments have been made. It is observed that with the exception of KOD (at Kodaikanal hill), situated on the southern Indian granulites having the thickest crust (~43.5 km), most of the Pan-African granulitic terranes have a crustal thicknesses of ~37 +/- 0.8km, with a transition to higher velocity at mid-crustal depths, and that their bulk composition is felsic. Average crustal VP/VS values (1.704 +/- 0.03) and thicknesses (37.8 +/- 0.8km), for four stations (SYO, PALK, TRV and ABPO), now located in East Antarctica, Sri Lanka, India and Madagascar, respectively, show remarkable similarity, indicating that the Pan-African orogeny was extensive enough to reorder the crustal structure of a wide region with a broadly similar stamp.

  17. Methods to determine the impact of rainfall on fuels and burned area in southern African savannas

    CSIR Research Space (South Africa)

    Archibald, S

    2010-11-01

    Full Text Available /Aux fins d'examen seulement Southern African re regimes as revealed by remote sensing S. Archibald1;2;6, R.J. Scholes1;2, D.P. Roy3, G.Roberts4, L. Boschetti5 April 9, 2010 1CSIR, Ecosystems Processes and Dynamics, PO Box 395, Pretoria 0001, South... densities have di erent e ects on the number of res per km2 and360 14 For Review Purposes Only/Aux fins d'examen seulement on the size of individual res. The number of ignitions increases with human population361 density, (Figure 7A) but there is a...

  18. Transport of plutonium by the Mississippi River system and other rivers in the southern United States

    International Nuclear Information System (INIS)

    Scott, M.R.; Salter, P.F.

    1987-01-01

    The distribution of fallout Pu has been studied in the sediments and water of the Mississippi River and eight other rivers. Plutonium content of the sediments is related to grain size and Fe and Mn content. Rivers in human climates show relatively high organic carbon (3 to 4%) and high /sup 239,240)Pu content (36 to 131 dpm/kg) in their suspended sediments. Dissolved Pu is very low in all the rivers; distribution coefficients vary from 10 4 to 10 5 . The 238 Pu//sup 239,240/Pu ratios are low in all the river sediments (∼.06) except the Miami River in Ohio, where ratios as high as 99 were measured. The high ratios originate from the Mound Laboratory Pu processing plant at Miamisburg, Ohio, and can be traced downstream to the junction with the Ohio River. Mississippi River suspended sediment shows a continual decrease of /sup 239,240/Pu content over a 7 year time period. An exponential curve best-fit through the data predicts a half time of decrease equal to 4.3 years. The decrease in Pu content of river sediment results from several factors: cessation of atmospheric weapons testing; transport of Pu to deeper levels of soil profiles; storage of sediment in flood plains and behind dams; and dilution by erosion by older, prebomb soil material. The amount of fallout Pu now removed from the Mississippi River drainage basin to the ocean is 11% as a maximum estimate. Most the fallout Pu in the Mississippi drainage basin will remain on the continent unless there are major changes in erosion and sediment transport patterns in the basin itself. 56 references, 7 figures, 2 tables

  19. Oxygen and Hydrogen Isotopic Characteristics of the Kaveri River Surface Waters, Southern Peninsular India

    International Nuclear Information System (INIS)

    Achyuthan, Hema; Michelini, Marzia; Sengupta, Somasis D.; Kale, Vishwas S.; Stenni, Barbara; Flora, Onelio

    2010-12-01

    We present in this paper the spatial distribution of stable isotopic composition (δ 18 O and δD) of Kaveri River surface waters to understand how the evaporation and precipitation affect the isotopic signature and dynamics of surface river waters. In the southern peninsular India, Kaveri River is one of the longest tropical river. Our stable isotope data indicate that the upper Kaveri region is influenced strongly by the SW monsoon. There is a narrow range between the δ 18 O values found from the origin of the Kaveri River to its delta, and there is no significant orographic impact of the Western Ghats. A decreasing trend of d values is found along the course of the river. This is attributed to evaporation effects, which nevertheless are not very strong. This difference in deuterium excess due to evaporation is also an indication of the moisture recycling in the lower Kaveri area, which is primarily controlled by evaporation from the wetlands in the delta plain but also from the surface waters and as such from the rivers. (author)

  20. Reemergence of rabies in the southern Han river region, Korea.

    Science.gov (United States)

    Oem, Jae-Ku; Kim, Seong-Hee; Kim, Yeon-Hee; Lee, Myoung-Heon; Lee, Kyoung-Ki

    2014-07-01

    Recently, 11 cases of animal rabies were reported in the southern region (Suwon and Hwaseong cities) of Gyeonggi Province, South Korea. The cases were temporally separated into two cases in dogs (Canis lupus familiaris) in spring 2012 and nine cases in domestic animals and wildlife in winter 2012-13. All carcasses were submitted for histopathologic examination and viral antigen identification. Sequences of the glycoprotein, nucleoprotein, and glycoprotein-large polymerase protein intergenic noncoding loci of the 11 strains were determined and compared with published reference sequences. All rabies strains were closely related to the Gangwon strains isolated in 2008-09, suggesting that the rabies virus strains isolated in Gyeonggi were introduced from Gangwon Province.

  1. High genetic connectivity among estuarine populations of the riverbream Acanthopagrus vagus along the southern African coast

    Science.gov (United States)

    Oosthuizen, Carel J.; Cowley, Paul D.; Kyle, Scotty R.; Bloomer, Paulette

    2016-12-01

    Physical and/or physiological constraints are assumed to isolate fish populations confined to or dependent on estuarine habitats. Strong isolation by distance is thus expected to affect connectivity. Such structuring has important implications for sustainable utilisation and replenishment of estuarine stocks that are heavily exploited. Here we present a preliminary investigation of the phylogenetic relationships of the riverbream (Acanthopagrus species) along the southern African coast and the geographic genetic structure of what appears to be a locally endemic species or lineage. Mitochondrial DNA (mtDNA) cytochrome b sequences support the notion that the species occurring along the southern African coast is A. vagus and not A. berda as previously thought. Yet, the taxonomy of this widespread Indo-West Pacific species or species-complex requires more in-depth investigation. No genetic differentiation was detected among estuarine populations of A. vagus based on the analyses of mtDNA ND2 gene sequences and 10 polymorphic nuclear microsatellite markers. The star-like genealogy and statistical analyses are consistent with a recent population expansion event. Spatial analyses of microsatellite genotypes fail to reject the null hypothesis of panmixia, indicative of a recent population expansion or ongoing gene flow between different estuaries. The northern localities were identified as containing most of the observed variation. This study not only provides insight into the phylogenetic relationship of A. vagus relative to other Acanthopagrus species but also sheds light on the demographic history and contemporary gene flow of the species.

  2. Relapsing fever causative agent in Southern Iran is a closely related species to East African borreliae.

    Science.gov (United States)

    Naddaf, Saied Reza; Ghazinezhad, Behnaz; Kazemirad, Elham; Cutler, Sally Jane

    2017-10-01

    We obtained two blood samples from relapsing fever patients residing in Jask County, Hormozgan Province, southern Iran in 2013. Sequencing of a partial fragment of glpQ from two samples, and further characterization of one of them by analyzing flaB gene, and 16S-23S spacer (IGS) revealed the greatest sequence identity with East African borreliae, Borrelia recurrentis, and Borrelia duttonii, and Borrelia microti from Iran. Phylogenetic analyses of glpQ, flaB, and concatenated sequences (glpQ, flab, and IGS) clustered these sequences amongst East African Relapsing fever borreliae and B. microti from Iran. However, the more discriminatory IGS disclosed a unique 8-bp signature (CAGCCTAA) separating these from B. microti and indeed other relapsing fever borreliae. In southern Iran, relapsing fever cases are mostly from localities in which O. erraticus ticks, the notorious vector of B. microti, prevail. There are chances that this argasid tick serves as a host and vector of several closely related species or ecotypes including the one we identified in the present study. The distribution of this Borrelia species remains to be elucidated, but it is assumed to be endemic to lowland areas of the Hormozgan Province, as well as Sistan va Baluchistan in the southeast and South Khorasan (in Persian: Khorasan-e Jonobi) in the east of Iran. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Dog rabies data reported to multinational organizations from Southern and Eastern African countries.

    Science.gov (United States)

    Beyene, Tariku Jibat; Mourits, Monique C M; Hogeveen, Henk

    2017-06-08

    Rabies is one of the viral diseases with the highest case fatality rate in humans. The main transmission route to humans is through bites, especially of infected dogs. Decisions on the allocation of resources to control and reduce the socio-economic impacts of rabies require reliable data. Several national, regional and international organizations have been gathering rabies data for more than a decade. The objective of this paper was to examine the consistencies in the number of dog rabies cases reported to different multinational organizations by Southern and Eastern African countries and to explore the presence of any time trend among the reported rabies data. Data was systematically extracted from the databases of the Southern and Eastern African Rabies Group-SEARG and the World Organization for Animal Health/World animal health information-OIE/WAHID. Despite differences in entities by which data have been reported to the two organisations, reported numbers were significantly correlated (Spearman's rho = 0.52, P rabies outbreaks. Inconsistencies in the reported numbers were observed between the databases, possibly due to the fact that human and animal health authorities report separately to the organisations involved in addition to the use of indefinite definitions of report categories set by report receiving organizations.

  4. Towards One Health Knowledge Networks: A Southern African Centre of Infectious Disease Surveillance case study

    Directory of Open Access Journals (Sweden)

    Eric Beda

    2012-06-01

    Full Text Available The dynamic nature of new information and/or knowledge is a big challenge for information systems. Early knowledge management systems focused entirely on technologies for storing, searching and retrieving data; these systems have proved a failure. Juirsica and Mylopoulos1 suggested that in order to build effective technologies for knowledge management, we need to further our understanding of how individuals, groups and organisations use knowledge. As the focus on knowledge management for organisations and consortia alike is moving towards a keen appreciation of how deeply knowledge is embedded in people’s experiences, there is a general realisation that knowledge cannot be stored or captured digitally. This puts more emphasis in creating enabling environments for interactions that stimulate knowledge sharing. Our work aims at developing an un-obtrusive intelligent system that glues together effective contemporary and traditional technologies to aid these interactions and manage the information captured. In addition this system will include tools to aid propagating a repository of scientific information relevant to surveillance of infectious diseases to complement knowledge shared and/or acts as a point of reference. This work is ongoing and based on experiences in developing a knowledge network management system for the Southern African Centre of Infectious Disease Surveillance (SACIDS, A One Health consortium of southern African academic and research institutions involved with infectious diseases of humans and animals in partnership with world-renowned centres of research in industrialised countries.

  5. Multiple origins of polyploidy in the phylogeny of southern African barbs (Cyprinidae) as inferred from mtDNA markers.

    Science.gov (United States)

    Tsigenopoulos, C S; Ráb, P; Naran, D; Berrebi, P

    2002-06-01

    The cyprinid genus Barbus, with more than 800 nominal species, is an apparently polyphyletic assemblage to which a number of unrelated species, groups and/or assemblages have been assigned. It includes species that exhibit three different ploidy levels: diploid, tetraploid and hexaploid. Several lineages of the family Cyprinidae constitute a major component of the African freshwater ichthyofauna, having about 500 species, and fishes assigned to the genus 'Barbus' have the most species on the continent. We used complete sequences of the mitochondrial cytochrome b gene in order to infer phylogenetic relationships between diploid, tetraploid and hexaploid species of 'Barbus' occurring in southern Africa, the only region where representatives of all of the three ploidy levels occur. The results indicate that most of the lineages are incorrectly classified in the genus 'Barbus'. The southern African tetraploids probably originated from southern African diploids. They constitute a monophyletic group distinct from tetraploids occurring in the Euro-Mediterranean region (Barbus sensu stricto). The 'small' African diploid species seem to be paraphyletic, while the 'large' African hexaploid barbs species are of a single, recent origin and form a monophyletic group. The evidence of multiple, independent origins of polyploidy occurring in the African cyprinine cyprinids thus provides a significant contribution to the knowledge on the systematic diversity of these fishes, and warrants a thorough taxonomic reorganization of the genus.

  6. The Nubian Complex of Dhofar, Oman: an African middle stone age industry in Southern Arabia.

    Directory of Open Access Journals (Sweden)

    Jeffrey I Rose

    Full Text Available Despite the numerous studies proposing early human population expansions from Africa into Arabia during the Late Pleistocene, no archaeological sites have yet been discovered in Arabia that resemble a specific African industry, which would indicate demographic exchange across the Red Sea. Here we report the discovery of a buried site and more than 100 new surface scatters in the Dhofar region of Oman belonging to a regionally-specific African lithic industry--the late Nubian Complex--known previously only from the northeast and Horn of Africa during Marine Isotope Stage 5, ∼128,000 to 74,000 years ago. Two optically stimulated luminescence age estimates from the open-air site of Aybut Al Auwal in Oman place the Arabian Nubian Complex at ∼106,000 years ago, providing archaeological evidence for the presence of a distinct northeast African Middle Stone Age technocomplex in southern Arabia sometime in the first half of Marine Isotope Stage 5.

  7. A taxonomic revision of the southern African native and naturalized species of Silene L. (Caryophyllaceae

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2012-12-01

    Full Text Available The native and naturalized species of Silene L. in southern Africa are reviewed, with full synonomy and the description of two new species from the West Coast of Western Cape. Eight native species and three naturalized species are recognized, including the first identification in southern Africa of the Mediterranean S. nocturna L. The identity of S. aethiopica Burm., which has remained unknown since its description, is established and is found to be the oldest name for S. clandestina Jacq. Patterns of morphological variation within each species are discussed and subspecies are recognized for geographically segregated groups of populations that are ± morphologically diagnosable. The following new names or combinations are made among the southern African taxa: S. aethiopica subsp. longiflora; S. burchellii subsp. modesta, subsp. multiflora, and subsp. pilosellifolia; S. crassifolia subsp. primuliflora; S. saldanhensis; S. rigens; and S. undulata subsp. polyantha. Each taxon is described, with information on ecology and distribution, and most species are illustrated, including SEM micrographs of the seeds.

  8. Groundwater quality characterization to protect biodiversity in SADC region (Southern African Development Community

    Directory of Open Access Journals (Sweden)

    Stefania Vitale

    2016-06-01

    Full Text Available The following paper describes the first phase of a study held in the context of the SECOSUD Phase II project, called “Conservation and equitable use of biological diversity in the SADC region (Southern African Development Community, which aims at promoting biodiversity conservation and sustainable economic development in the SADC [1]. The Southern African Development Community (SADC is an inter-governmental organization, with 15 member states: Angola, Botswana, Democratic Republic of Congo, Lesotho, Mauritius, Malawi, Mozambique, Namibia, Madagascar, Seychelles, South Africa, Swaziland, Tanzania, Zambia, and Zimbabwe. Its aim is to increase socio-economic cooperation and integration among the community. It is one of the richest area in terms of biodiversity. The main goal of the Project is to contribute to stop biodiversity loss by supporting the development of conservation strategies. Biodiversity or biological diversity is formally defined by the Convention on Biological Diversity (CBD as: “the variability among living organisms from all sources including, among others, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems” (UN 1992 Article 2 [2]. Biodiversity is affected by the interaction of multiple drivers and pressures including demographic, economic, socio-political, scientific and technological ones, which are leading to further decline, degradation and loss. The principal pressures on biodiversity include habitat loss and degradation, overexploitation, alien invasive species, climate change and pollution. These pressures are continuing to increase. To use biodiversity and to keep it in a sustainable way, it is necessary to study it, assess its economic value, develop a global strategy and a global network to monitor its status in the biosphere. An important step in developing conservation of biodiversity

  9. Effects of repeated burning on woody vegetation structure and composition in a semi-arid southern African savanna

    NARCIS (Netherlands)

    Gandiwa, E.

    2011-01-01

    The objective of this study was to investigate the effects of repeated dry season annual hot fires on woody plants in a semiarid southern African savanna in Zimbabwe. Parts of the National University of Science and Technology (NUST) research fields in Bulawayo, Zimbabwe have been burnt annually in

  10. Compiling an Evidence-Based Improvement Plan for the Support of Distance-Education Students at a Southern African University

    Science.gov (United States)

    Makhakhane, Bothephana; Wilkinson, Annette C.; Ndeya-Ndereya, Charity N.

    2016-01-01

    This article illustrates how an event guide can be used to organise, systematise and prioritise the large amount of findings from an extensive study. The study aimed to enhance student support at a distance-education institute in a Southern African country (Lesotho). In this case study an improvement-oriented evaluation of the strengths,…

  11. Mainstreaming biodiversity and wildlife management into climate change policy frameworks in selected east and southern African countries

    Directory of Open Access Journals (Sweden)

    Olga L. Kupika

    2016-04-01

    Full Text Available The Rio+20 outcomes document, the Future We Want, enshrines green economy as one of the platforms to attain sustainable development and calls for measures that seek to address climate change and biodiversity management. This paper audits climate change policies from selected east and southern African countries to determine the extent to which climate change legislation mainstreams biodiversity and wildlife management. A scan of international, continental, regional and national climate change policies was conducted to assess whether they include biodiversity and/or wildlife management issues. The key finding is that many climate change policy–related documents, particularly the National Adaptation Programme of Actions (NAPAs, address threats to biodiversity and wildlife resources. However, international policies like the United Nations Framework Convention on Climate Change and Kyoto Protocol do not address the matter under deliberation. Regional climate change policies such as the East African Community, Common Market for Eastern and Southern Africa and African Union address biodiversity and/or wildlife issues whilst the Southern African Development Community region does not have a stand-alone policy for climate change. Progressive countries like Rwanda, Uganda, Tanzania and Zambia have recently put in place detailed NAPAs which are mainstream responsive strategies intended to address climate change adaptation in the wildlife sector. Keywords: mainstreaming, biodiversity, wildlife, climate change policy, east and southern Africa

  12. Reproductive system and the spermatophoric reaction of the mesopelagic squid Octopoteuthis sicula (Ruppell 1844) (Cephalopoda : Octopoteuthidae) from southern African waters

    NARCIS (Netherlands)

    Hoving, H. J. T.; Lipinski, M. R.; Videler, J. J.

    2008-01-01

    Reproductive features of the poorly known oceanic squid Octopoteuthis sicula are described and quantified to gain insight into the reproductive biology of the species. The data are based on 39 complete and partial specimens from southern African waters, collected between 1975 and 2005. The specimens

  13. Phylogenetic studies of Terfezia pfeilii and Choiromyces echinulatus (Pezizales) support new genera for southern African truffles: Kalaharituber and Eremiomyces.

    Science.gov (United States)

    Yael Ferdman; Sharon Aviram; Nurit Roth-Bejerano; James M. Trappe; Varda. Kagan-Zur

    2005-01-01

    The ITS region including the 5.8S rRNA gene as well as the 5' end of the 28S rRNA gene of hypogeous Pezizaceae and Tuberaceae were studied to clarify the generic placement of two southern African desert truffles, Terfezia pfeilii and Choiromyces echinulatus. The results show that...

  14. On the stationarity of Floods in west African rivers

    Science.gov (United States)

    NKA, B. N.; Oudin, L.; Karambiri, H.; Ribstein, P.; Paturel, J. E.

    2014-12-01

    West Africa undergoes a big change since the years 1970-1990, characterized by very low precipitation amounts, leading to low stream flows in river basins, except in the Sahelian region where the impact of human activities where pointed out to justify the substantial increase of floods in some catchments. More recently, studies showed an increase in the frequency of intense rainfall events, and according to observations made over the region, increase of flood events is also noticeable during the rainy season. Therefore, the assumption of stationarity on flood events is questionable and the reliability of flood evolution and climatic patterns is justified. In this work, we analyzed the trends of floods events for several catchments in the Sahelian and Sudanian regions of Burkina Faso. We used thirteen tributaries of large river basins (Niger, Nakambe, Mouhoun, Comoé) for which daily rainfall and flow data were collected from national hydrological and meteorological services of the country. We used Mann-Kendall and Pettitt tests to detect trends and break points in the annual time series of 8 rainfall indices and the annual maximum discharge records. We compare the trends of precipitation indices and flood size records to analyze the possible causality link between floods size and rainfall pattern. We also analyze the stationary of the frequency of flood exceeding the ten year return period level. The samples were extracted by a Peak over threshold method and the quantification of change in flood frequency was assessed by using a test developed by Lang M. (1995). The results exhibit two principal behaviors. Generally speaking, no trend is detected on catchments annual maximum discharge, but positive break points are pointed out in a group of three right bank tributaries of the Niger river that are located in the sahelian region between 300mm to 650mm. These same catchments show as well an increase of the yearly number of flood greater than the ten year flood since

  15. The isolation and localization of arbitrary restriction fragment length polymorphisms in Southern African populations

    International Nuclear Information System (INIS)

    Conn, V.

    1987-01-01

    The main aim of this study was to contribute to the mapping of the human genome by searching for and characterizing a number of RFLPs (restriction fragment length polymorphisms) in the human genome. The more specific aims of this study were: 1. To isolate single-copy human DNA sequences from a human genomic library. 2. To use these single-copy sequences as DNA probes to search for polymorphic variation among Caucasoid individuals. 3. To show by means of family studies that the RFLPs were inherited in a co-dominant Mendelian fashion. 4. To determine the population frequencies of these RFLPs in Southern African Populations, namely the Bantu-speaking Negroids and the San. 5. To assign these RFLP-detecting DNA sequences to human chromosomes using somatic cell hybrid lines. In this study DNA was labelled with Phosphorus 32

  16. Spatio temporal population dynamics of the invasive diatom Didymosphenia geminata in central-southern Chilean rivers.

    Science.gov (United States)

    Montecino, V; Molina, X; Bothwell, M; Muñoz, P; Carrevedo, M L; Salinas, F; Kumar, S; Castillo, M L; Bizama, G; Bustamante, R O

    2016-10-15

    We document the distribution of Didymosphenia geminata in central-southern Chilean rivers and identify the chemical and physical factors associated with its presence/absence (p/a). Repeated surveys in five successive years provided evidence that D. geminata could be nearing a biogeographic equilibrium in the region. D. geminata databases from extensive biological and environmental surveys in 187 rivers, within ten catchments, south of 38°S commenced in November 2010 and ran through May 2013. In addition, data from two other field surveys were used. The sites evenly distributed latitudinally were climatically characterized. The recent sampling program, following a published species distribution model, was designed to explore D. geminata distribution within thirteen catchments (34°S-48°S). An extensive river survey in 2014 (spring-summer) and in 2015 (autumn) included the p/a, and relative abundance of D. geminata cells in phytobenthos and in the drift. These p/a results showed that the probability of re-encountering D. geminata cells at sites where the species was previously found was significantly high while the probability of finding D. geminata cells at sites previously without the species was significantly low. This suggests that the distribution of D. geminata cells among suitable habitats was nearing completion. The relative abundance of D. geminata cells in the phytobenthos versus in the drift indicates seasonality with higher proportion of cells in the phytobenthos during the spring-summer than during the autumn. During the final surveys, principal component analysis of chemical and physical characteristics of rivers showed significant differences between rivers with and without D. geminata. Based on our observations of the distribution of D. geminata cells among rivers with suitable habitat conditions and the fluctuating rate of spread between rivers, we conclude that D. geminata is probably in the ending stage of its spatial demographic expansion in

  17. Cadmium distribution in sediment profiles of the six main rivers in southern Taiwan

    International Nuclear Information System (INIS)

    Tsai Lijyur; Yu Kuangchung; Ho, S.-T.

    2007-01-01

    Dynamic cadmium distribution has been studied in six main rivers flowing through the largest, most highly developed and polluted area of southern Taiwan. Sediment profile samples were also analyzed for Cu, Cr, Zn, Ni, Pb, Co, Mn, Fe, carbonates, Mn-oxides, Fe-oxides and organic matter in order to characterize the geochemical environment and to identify the pollutant sources. Higher Cd concentrations (about 3.5 mg/kg) at depths of 0-10 cm have been detected in the samples of Yenshui, Ell-ren and Potzu rivers, associated to the history of industrial activity in their catchments. According to the linear correlation coefficient (r) between Cd and the geochemical components, carbonates are the primary Cd binding phase in the Ell-ren river (r = 0.85), and Cd comes from the same pollutant sources of those containing Cr, Ni, Cu and Zn (r > 0.80). Cadmium concentration in the Potzu and Peikang river sediments is probably due to waste deposits rich in Cr and Cu (0.54 < r < 0.65). In the case of the Yenshui river, there is only a weak indication that cadmium derives from waste material containing Cr, Ni, Cu, Zn, and Pb (r around 0.40). On the other hand, in the Tsengwen and Chishui sediments cadmium concentrations seem to represent natural background. Generally, the Ell-ren and Yenshui rivers show strong heavy metal pollution, while no important heavy metal contamination has been found in the Tsengwen, Potzu, Chishui, and Peikang rivers

  18. Vertical slip rates of active faults of southern Albania inferred from river terraces

    Directory of Open Access Journals (Sweden)

    Oswaldo Guzmán

    2014-02-01

    Full Text Available Fluvial terraces of Shkumbin, Devoll, Osum and Vjosa rivers (southern Albania and northwestern Greece are studied in order to quantify the vertical slip rates of the large active faults of the Dinaric-Albanic-Hellenic Alpine fold belt. The spatial and temporal variations of the incision rates along these rivers were estimated from the geomorphological mapping of the Quaternary sediments, the geometry and the dating of the terraces. Eleven terraces levels were identified in Albania from 68 geochronological ages already published or acquired for this work. The five lower terraces of the four studied rivers are well dated (10 new and 23 already published ages. These terraces are younger than 30 ka and their remnants are numerous. Their restoration allows estimating the regional trend of incision rate and the identification of local shifts. We argue that these shifts are linked to the active tectonics when they coincide with the faults already mapped by previous authors. Vertical slip rates for eight active faults in southern Albania are thus estimated for the last 19 ka and vary from ~0.1 to ~2 mm/a. The Lushnje Tepelene Thrust, that extends more than 120 kilometers, has a throw rate that varies from 0.2 to 0.8 mm/a, whereas the active faults of the extensional domain are segmented but are very active, with throw rates reaching locally 2 mm/a.

  19. A southern African origin and cryptic structure in the highly mobile plains zebra.

    Science.gov (United States)

    Pedersen, Casper-Emil T; Albrechtsen, Anders; Etter, Paul D; Johnson, Eric A; Orlando, Ludovic; Chikhi, Lounes; Siegismund, Hans R; Heller, Rasmus

    2018-03-01

    The plains zebra (Equus quagga) is an ecologically important species of the African savannah. It is also one of the most numerous and widely distributed ungulates, and six subspecies have been described based on morphological variation. However, the within-species evolutionary processes have been difficult to resolve due to its high mobility and a lack of consensus regarding the population structure. We obtained genome-wide DNA polymorphism data from more than 167,000 loci for 59 plains zebras from across the species range, encompassing all recognized extant subspecies, as well as three mountain zebras (Equus zebra) and three Grevy's zebras (Equus grevyi). Surprisingly, the population genetic structure does not mirror the morphology-based subspecies delineation, underlining the dangers of basing management units exclusively on morphological variation. We use demographic modelling to provide insights into the past phylogeography of the species. The results identify a southern African location as the most likely source region from which all extant populations expanded around 370,000 years ago. We show evidence for inclusion of the extinct and phenotypically divergent quagga (Equus quagga quagga) in the plains zebra variation and reveal that it was less divergent from the other subspecies than the northernmost (Ugandan) extant population.

  20. Re-Os dating of molybdenites from Southern India: implication for Pan-African metallogeny

    International Nuclear Information System (INIS)

    Santosh, M.; Suzuki, Katsuhiko; Masuda, Akimasa

    1994-01-01

    Rhenium-osmium (Re-Os) dating of two molybdenite samples from the alkali granite and pegmatite of Ambalavayal in northern Kerala (S. India) yielded ages of 567 ±28 Ma and 566±77 Ma, respectively. These ages closely compare with the previously determined Rb-Sr whole rock age of 595±20 Ma Rb-Sr for granite, and K-Ar biotite age of 560±30 Ma for the pegmatite. Our study provides the first direct determination of the timing of ore mineralization associated with felsic magmatism in southern India, and reveals the fingerprints of a prominent Pan-African metallogenic event. This timing coincides with the formation of rare metal and gemstone-bearing pegmatites in different parts of southern India, Sri Lanka, Madagascar and East Antarctica. In most cases, the mineralizations are genetically related to felsic magmas emplaced along structural conduits, suggesting that the magmatism and metallogeny are related to deep-seated extension in the cratonized crustal segments of the Gondwana assembly. (author). 20 refs., 3 figs., 1 tab

  1. Optimising trans-national power generation and transmission investments: a Southern African example

    International Nuclear Information System (INIS)

    Graeber, Bernhard; Spalding-Fecher, Randall; Gonah, Brian

    2005-01-01

    Increased integration and co-operation within the Southern African power sector has opened up significant opportunities for reducing the economic and environmental costs of meeting increasing electricity demand in Southern Africa. This paper applies a linear programming model to investigate the economic and environmental benefits of regional integrated planning for electricity, and the impact of including environmental costs in the decision-making process. We find that, from a financial perspective, optimising generation and transmission investments in the region would result in savings of dollar 2-4 billion over 20 years, or 5% of total system costs. Introducing a tax based on the external damage costs of carbon dioxide as part of the decision-making process would result in moderate increases in financial costs (15-20%), but would reduce regional carbon emissions by up to 55% at a mitigation cost of dollar 11 per tonne of carbon dioxide. This raises the possibility of financing regional power projects with Clean Development Mechanism funding, which we explore with an example

  2. IDESSA: An Integrative Decision Support System for Sustainable Rangeland Management in Southern African Savannas

    Science.gov (United States)

    Meyer, Hanna; Authmann, Christian; Dreber, Niels; Hess, Bastian; Kellner, Klaus; Morgenthal, Theunis; Nauss, Thomas; Seeger, Bernhard; Tsvuura, Zivanai; Wiegand, Kerstin

    2017-04-01

    Bush encroachment is a syndrome of land degradation that occurs in many savannas including those of southern Africa. The increase in density, cover or biomass of woody vegetation often has negative effects on a range of ecosystem functions and services, which are hardly reversible. However, despite its importance, neither the causes of bush encroachment, nor the consequences of different resource management strategies to combat or mitigate related shifts in savanna states are fully understood. The project "IDESSA" (An Integrative Decision Support System for Sustainable Rangeland Management in Southern African Savannas) aims to improve the understanding of the complex interplays between land use, climate patterns and vegetation dynamics and to implement an integrative monitoring and decision-support system for the sustainable management of different savanna types. For this purpose, IDESSA follows an innovative approach that integrates local knowledge, botanical surveys, remote-sensing and machine-learning based time-series of atmospheric and land-cover dynamics, spatially explicit simulation modeling and analytical database management. The integration of the heterogeneous data will be implemented in a user oriented database infrastructure and scientific workflow system. Accessible via web-based interfaces, this database and analysis system will allow scientists to manage and analyze monitoring data and scenario computations, as well as allow stakeholders (e. g. land users, policy makers) to retrieve current ecosystem information and seasonal outlooks. We present the concept of the project and show preliminary results of the realization steps towards the integrative savanna management and decision-support system.

  3. Implementing the millennium development food security goals Challenges of the southern African context

    Science.gov (United States)

    Love, David; Twomlow, Steve; Mupangwa, Walter; van der Zaag, Pieter; Gumbo, Bekithemba

    The Millennium Development Goals’ target to halve the proportion of people who suffer from hunger is extremely important in southern Africa, where food security has become increasingly problematic over the last 20 years. One “quick-win” proposal is replenishment of soil nutrients for smallholder farmers, through free or subsidised chemical fertilisers. Other proposals include appropriate irrigation technology, improved inputs and interventions targeted at women. Analysis of over 10 years of agro-hydrological and agro-economic studies from southern African show that a different approach is required to interventions proposed. There are sustainability problems with free chemical fertiliser due to transport costs and ancillary costs. Furthermore, recent studies in Zimbabwe and Mozambique show that significant increases in yield can only be obtained when soil fertility management is combined with good crop husbandry, e.g. timely planting and weeding. Ongoing replenishment of fertility would be dependent on a continued free or subsidised fertiliser supply, and transport system. Increasing access to irrigation will help, but is not the only solution and cannot reach even a majority of farmers. It has been determined that short dryspells are often the major cause of low yields in sub-Saharan Africa. Soil-water conservation approaches, e.g. winter weeding and conservation tillage, can reduce risk and increase yield. The following specific recommendations are made for urgent interventions to contribute sustainably to food security in southern Africa: (i) To increases access to fertiliser, consider development of strong input markets at end-user level. (ii) Intensification of technology transfer, focusing on capacity building for transfer of existing technologies and much closer collaboration between state and NGO sectors, agronomists and water engineers. (iii) Increasing the uptake of soil-water conservation methods, including conservation tillage and weeding, and

  4. Towards One Health disease surveillance: The Southern African Centre for Infectious Disease Surveillance approach

    Directory of Open Access Journals (Sweden)

    Esron D. Karimuribo

    2012-06-01

    Full Text Available Africa has the highest burden of infectious diseases in the world and yet the least capacity for its risk management. It has therefore become increasingly important to search for ‘fit-for- purpose’ approaches to infectious disease surveillance and thereby targeted disease control. The fact that the majority of human infectious diseases are originally of animal origin means we have to consider One Health (OH approaches which require inter-sectoral collaboration for custom-made infectious disease surveillance in the endemic settings of Africa. A baseline survey was conducted to assess the current status and performance of human and animal health surveillance systems and subsequently a strategy towards OH surveillance system was developed. The strategy focused on assessing the combination of participatory epidemiological approaches and the deployment of mobile technologies to enhance the effectiveness of disease alerts and surveillance at the point of occurrence, which often lies in remote areas. We selected three study sites, namely the Ngorongoro, Kagera River basin and Zambezi River basin ecosystems. We have piloted and introduced the next-generation Android mobile phones running the EpiCollect application developed by Imperial College to aid geo-spatial and clinical data capture and transmission of this data from the field to the remote Information Technology (IT servers at the research hubs for storage, analysis, feedback and reporting. We expect that the combination of participatory epidemiology and technology will significantly improve OH disease surveillance in southern Africa.

  5. Towards one health disease surveillance: the Southern African Centre for Infectious Disease Surveillance approach.

    Science.gov (United States)

    Karimuribo, Esron D; Sayalel, Kuya; Beda, Eric; Short, Nick; Wambura, Philemon; Mboera, Leonard G; Kusiluka, Lughano J M; Rweyemamu, Mark M

    2012-06-20

    Africa has the highest burden of infectious diseases in the world and yet the least capacity for its risk management. It has therefore become increasingly important to search for 'fit-for- purpose' approaches to infectious disease surveillance and thereby targeted disease control. The fact that the majority of human infectious diseases are originally of animal origin means we have to consider One Health (OH) approaches which require inter-sectoral collaboration for custom-made infectious disease surveillance in the endemic settings of Africa. A baseline survey was conducted to assess the current status and performance of human and animal health surveillance systems and subsequently a strategy towards OH surveillance system was developed. The strategy focused on assessing the combination of participatory epidemiological approaches and the deployment of mobile technologies to enhance the effectiveness of disease alerts and surveillance at the point of occurrence, which often lies in remote areas. We selected three study sites, namely the Ngorongoro, Kagera River basin and Zambezi River basin ecosystems. We have piloted and introduced the next-generation Android mobile phones running the EpiCollect application developed by Imperial College to aid geo-spatial and clinical data capture and transmission of this data from the field to the remote Information Technology (IT) servers at the research hubs for storage, analysis, feedback and reporting. We expect that the combination of participatory epidemiology and technology will significantly improve OH disease surveillance in southern Africa.

  6. Niger River Discharge and the Connection to the West African Monsoon Over the Last 25 kyr

    Science.gov (United States)

    Patten, J.; Marcantonio, F.; Slowey, N. C.; Schmidt, M. W.; Parker, A. O.; Thomas, D. J.

    2016-12-01

    The intensity of the West African monsoon is directly tied to the shifting of the Inter-Tropical Convergence Zone and global-scale climate variability. As the West African monsoon varies through time, it affects the precipitation that occurs within the Niger River basin and the Niger River's discharge into the eastern equatorial Atlantic Ocean. The accumulation of marine sediments on the continental slope offshore of the Niger Delta reflects these processes. We seek to better understand how related environmental processes have varied as climate and sea level changed during the latter part of the last glacial-interglacial cycle. Here we present results from our ongoing investigation of sediments collected offshore of the Niger Delta that reflect such changes. The concentrations of 230Th, 232Th, and 234U in the sediments have been measured and combined with ages from radiocarbon dates and planktonic foraminiferal δ18O stratigraphies to estimate how the rate of sediment accumulation has varied through time. This record is considered together with measurements of sediment CaCO3 content and grain-size distribution to better understand the relative importance of environmental processes that control the flux of sediments and thorium to the seafloor - scavenging by particles settling through the water column versus the transport of sediments downslope by turbidity flows. We present xs230Th-derived 232Th fluxes that we suggest approximate the amount of fine-grained detrital material delivered from the Niger River to our sites. We anticipate that the importance of these competing processes will vary as climate/sea-level change influences the flux of sediments from the Niger River and the transport of these sediments to the slope.

  7. Environmental geophysics at the Southern Bush River Peninsula, Aberdeen Proving Ground, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Davies, B.E.; Miller, S.F.; McGinnis, L.D. [and others

    1995-05-01

    Geophysical studies have been conducted at five sites in the southern Bush River Peninsula in the Edgewood Area of Aberdeen Proving Ground, Maryland. The goals of the studies were to identify areas containing buried metallic objects and to provide diagnostic signatures of the hydrogeologic framework of the site. These studies indicate that, during the Pleistocene Epoch, alternating stands of high and low sea level resulted in a complex pattern of channel-fill deposits. Paleochannels of various sizes and orientations have been mapped throughout the study area by means of ground-penetrating radar and EM-31 techniques. The EM-31 paleochannel signatures are represented onshore either by conductivity highs or lows, depending on the depths and facies of the fill sequences. A companion study shows the features as conductivity highs where they extend offshore. This erosional and depositional system is environmentally significant because of the role it plays in the shallow groundwater flow regime beneath the site. Magnetic and electromagnetic anomalies outline surficial and buried debris throughout the areas surveyed. On the basis of geophysical measurements, large-scale (i.e., tens of feet) landfilling has not been found in the southern Bush River Peninsula, though smaller-scale dumping of metallic debris and/or munitions cannot be ruled out.

  8. Evaluation of water quality at the source of streams of the Sinos River Basin, southern Brazil

    Directory of Open Access Journals (Sweden)

    T Benvenuti

    Full Text Available The Sinos River Basin (SRB is located in the northeastern region of the state of Rio Grande do Sul (29º20' to 30º10'S and 50º15' to 51º20'W, southern Brazil, and covers two geomorphologic provinces: the southern plateau and the central depression. It is part of the Guaíba basin, has an area of approximately 800 km2 and contains 32 counties. The basin provides drinking water for 1.6 million inhabitants in one of the most important industrial centres in Brazil. This study describes different water quality indices (WQI used for the sub-basins of three important streams in the SRB: Pampa, Estância Velha/Portão and Schmidt streams. Physical, chemical and microbiological parameters assessed bimonthly using samples collected at each stream source were used to calculate the Horton Index (HI, the Dinius Index (DI and the water quality index adopted by the US National Sanitation Foundation (NSF WQI in the additive and multiplicative forms. These indices describe mean water quality levels at the streams sources. The results obtained for these 3 indexes showed a worrying scenario in which water quality has already been negatively affected at the sites where three important sub-basins in the Sinos River Basin begin to form.

  9. Recent, climate-driven river incision rate fluctuations in the Mercantour crystalline massif, southern French Alps

    Science.gov (United States)

    Petit, C.; Goren, L.; Rolland, Y.; Bourlès, D.; Braucher, R.; Saillard, M.; Cassol, D.

    2017-06-01

    We present a new geomorphological analysis of the Tinée River tributaries in the southern French Alps based on numerical inverse and forward modelling of their longitudinal profiles. We model their relative uplift history with respect to the main channel, hence the incision rate history of this channel. Inverse models show that all tributaries have consistent incision rate histories with alternating high and low values. A comparison with global temperature curves shows that these variations correlate with quaternary climate changes. We suggest that during warm periods, a wave of regressive erosion propagates in the Tinée River, while its tributaries deeply incise their substratum to catch up with the falling base-level. We also show that the post 140 ka history of this landscape evolution is dominated by fluvial incision. We then perform forward models of river incision and simulate the incision of the Tinée River system over a time span of 600 ka. This model allows us to extract time and space incision rate variations of the Tinée River. With a background of a few mm.yr-1, incision rate can increase up to more than 1 cm yr-1 during short periods of time due to climatic oscillations. This result is compatible with published cosmogenic nuclide based dating, which evidenced incision rates from 0.2 to 24 mm yr-1. The part of the channel located between 12 and 20 km downstream from the source has undergone several periods of rapid incision rates, which could explain the steep hillslopes and the triggering of a landslide ∼10 ka ago.

  10. Modeling of soil erosion and sediment transport in the East River Basin in southern China

    Science.gov (United States)

    Wu, Yping; Chen, Ji

    2012-01-01

    Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide.

  11. Modeling of soil erosion and sediment transport in the East River Basin in southern China.

    Science.gov (United States)

    Wu, Yiping; Chen, Ji

    2012-12-15

    Soil erosion is a major global environmental problem that has caused many issues involving land degradation, sedimentation of waterways, ecological degradation, and nonpoint source pollution. Therefore, it is significant to understand the processes of soil erosion and sediment transport along rivers, and this can help identify the erosion prone areas and find potential measures to alleviate the environmental effects. In this study, we investigated soil erosion and identified the most seriously eroded areas in the East River Basin in southern China using a physically-based model, Soil and Water Assessment Tool (SWAT). We also introduced a classical sediment transport method (Zhang) into SWAT and compared it with the built-in Bagnold method in simulating sediment transport process along the river. The derived spatial soil erosion map and land use based erosion levels can explicitly illustrate the identification and prioritization of the critical soil erosion areas in this basin. Our results also indicate that erosion is quite sensitive to soil properties and slope. Comparison of Bagnold and Zhang methods shows that the latter can give an overall better performance especially in tracking the peak and low sediment concentrations along the river. We also found that the East River is mainly characterized by sediment deposition in most of the segments and at most times of a year. Overall, the results presented in this paper can provide decision support for watershed managers about where the best management practices (conservation measures) can be implemented effectively and at low cost. The methods we used in this study can also be of interest in sediment modeling for other basins worldwide. Published by Elsevier B.V.

  12. Fossil imprints of the Pan-African collision process revealed by seismic anisotropy in southern Madagasca

    Science.gov (United States)

    Tilmann, F. J.; Rindraharisaona, E. J.; Reiss, M. C.; Dreiling, J.; Rumpker, G.; Yuan, X.; Giese, J.; Priestley, K. F.; Wysession, M. E.; Barruol, G.; Rambolamanana, G.

    2017-12-01

    In the assembly of Pangaea during the Proterozoic Pan-African Orogeny and later rifting and break-up of Gondwanaland, Madagascar occupied a central position, sandwiched between East Africa and India-Seychelles. Today, its metamorphic terranes still bear witness to the collision process. In the SELASOMA project we have deployed a seismic array in southern Madagascar in order to determine the imprint of these events onto the present day-crustal structure. 25 broadband and 23 SP stations were deployed for a period of 1-2 years. We present an overview of the results of several studies (receiver functions, ambient noise surface wave analysis, SKS splitting) constraining the isotropic and anisotropic crustal structure of southern Madagascar based on this deployment, supplemented by permanent stations and the contemporaneous MACOMO and RHUM-RUM deployments. The upper and middle crust of the Archean and Proterozoic provinces is overall quite similar, but a remarkable difference is that the Archean crust shows clear signs of underplating; we surmise that the Proterozoic crust was lost in the Pan-African collision. Both horizontal (from shear-wave splitting) and radial (SH/SV from Love and Rayleigh discrepancy) anisotropy shows evidence of collisional processes. A 150 km-wide zone of anomalous splitting measurements (deviating from the APM-parallel fast directions in most of Madagascar) in the region, where several major fossil shear zones have been mapped, can be explained as a zone of extensive coherent deformation within the crust; fast directions here align with the dominant strike of the major fossil shear zones. Negative radial anisotropy (i.e., SV faster than SH) in the mid-crust, likewise interpreted to have been formed by the collision, highlights the likely role of vertical shearing, presumably caused by extensive folding. In the lower crust, however, positive radial anisotropy is found in most of the Proterozoic and Archean terranes, which, analogous to the

  13. A One Health Evaluation of the Southern African Centre for Infectious Disease Surveillance

    Directory of Open Access Journals (Sweden)

    Marie C. E. Hanin

    2018-03-01

    Full Text Available Rooted in the recognition that emerging infectious diseases occur at the interface of human, animal, and ecosystem health, the Southern African Centre for Infectious Disease Surveillance (SACIDS initiative aims to promote a trans-sectoral approach to address better infectious disease risk management in five countries of the Southern African Development Community. Nine years after SACIDS’ inception, this study aimed to evaluate the program by applying a One Health (OH evaluation framework developed by the Network for Evaluation of One Health (NEOH. The evaluation included a description of the context and the initiative, illustration of the theory of change, identification of outputs and outcomes, and assessment of the One Healthness. The latter is the sum of characteristics that defines an integrated approach and includes OH thinking, OH planning, OH working, sharing infrastructure, learning infrastructure, and systemic organization. The protocols made available by NEOH were used to develop data collection protocols and identify the study design. The framework relies on a mixed methods approach by combining a descriptive and qualitative assessment with a semi-quantitative evaluation (scoring. Data for the analysis were gathered during a document review, in group and individual interviews and in an online survey. Operational aspects (i.e., OH thinking, planning, and working were found to be balanced overall with the highest score in the planning dimension, whereas the infrastructure (learning infrastructure, systemic organization, and sharing infrastructure was high for the first two dimensions, but low for sharing. The OH index calculated was 0.359, and the OH ratio calculated was 1.495. The program was praised for its great innovative energy in a difficult landscape dominated by poor infrastructure and its ability to create awareness for OH and enthuse people for the concept; training of people and networking. Shortcomings were identified

  14. Pleistocene aridification cycles shaped the contemporary genetic architecture of Southern African baboons.

    Directory of Open Access Journals (Sweden)

    Riashna Sithaldeen

    Full Text Available Plio-Pleistocene environmental change influenced the evolutionary history of many animal lineages in Africa, highlighting key roles for both climate and tectonics in the evolution of Africa's faunal diversity. Here, we explore diversification in the southern African chacma baboon Papio ursinus sensu lato and reveal a dominant role for increasingly arid landscapes during past glacial cycles in shaping contemporary genetic structure. Recent work on baboons (Papio spp. supports complex lineage structuring with a dominant pulse of diversification occurring 1-2Ma, and yet the link to palaeoenvironmental change remains largely untested. Phylogeographic reconstruction based on mitochondrial DNA sequence data supports a scenario where chacma baboon populations were likely restricted to refugia during periods of regional cooling and drying through the Late Pleistocene. The two lineages of chacma baboon, ursinus and griseipes, are strongly geographically structured, and demographic reconstruction together with spatial analysis of genetic variation point to possible climate-driven isolating events where baboons may have retreated to more optimum conditions during cooler, drier periods. Our analysis highlights a period of continuous population growth beginning in the Middle to Late Pleistocene in both the ursinus and the PG2 griseipes lineages. All three clades identified in the study then enter a state of declining population size (Nef through to the Holocene; this is particularly marked in the last 20,000 years, most likely coincident with the Last Glacial Maximum. The pattern recovered here conforms to expectations based on the dynamic regional climate trends in southern Africa through the Pleistocene and provides further support for complex patterns of diversification in the region's biodiversity.

  15. Measuring conditions and trends in ecosystem services at multiple scales: the Southern African Millennium Ecosystem Assessment (SAfMA) experience

    OpenAIRE

    van Jaarsveld, A.S; Biggs, R; Scholes, R.J; Bohensky, E; Reyers, B; Lynam, T; Musvoto, C; Fabricius, C

    2005-01-01

    The Southern African Millennium Ecosystem Assessment (SAfMA) evaluated the relationships between ecosystem services and human well-being at multiple scales, ranging from local through to sub-continental. Trends in ecosystem services (fresh water, food, fuel-wood, cultural and biodiversity) over the period 1990-2000 were mixed across scales. Freshwater resources appear strained across the continent with large numbers of people not securing adequate supplies, especially of good quality water. T...

  16. Paleomagnetism and tectonic evolution of the Pan-African Damara Belt, southern Africa

    Science.gov (United States)

    McWilliams, M. O.; KröNer, A.

    1981-06-01

    Paleomagnetic results are reported from the Nosib, Otavi, and Mulden groups of the Damara Supergroup, a late Precambrian shelf sequence on the southern margin of the Congo craton in Namibia. Three magnetizations were isolated in the Nosib group samples. In order of decreasing blocking temperature they are NQ1 (n = 6 sites, λ = 28°N, ϕ = 323°E, α95 = 15°), NQ2 (n = 7 sites, λ = 51°S, ϕ = 213°E, α95 = 12°), and NQ3 (n = 13 samples, λ = 09°N, ϕ = 295°E, α95 = 13°). Overall precision of all three magnetizations upon tectonic correction suggests that they predate Pan-African (650-450 Ma) folding. Two magnetizations were isolated in the Otavi group samples, above the Nosib in stratigraphic sequence. The DC1 component of possible prefolding age (n = 4 sites, λ = 52°S, ϕ = 186°E, α95 = 35°) has been over-printed by the DC2 magnetization (n = 10 sites, λ = 55°S, ϕ = 044°E, α95 = 15°) of probable postfolding age. A single magnetization of probable pre-folding age was isolated in the overlying Mulden Group samples (n = 6 sites, λ = 12°S, ϕ = 090°E, α95 = 16°). Together with previously published paleomagnetic data from Africa, the new data showed that no great relative movements have occurred between the Congo and Kalahari cratons during the interval of Pan-African tectonism in the Damara belt (McElhinny and McWilliams, 1977). Continental collision preceded by large relative displacements and closure of a wide ocean (e.g., a Himalayan analog) is effectively ruled out for the Damara belt. We develop an alternative model consistent with the available paleomagnetic and geologic data, which invokes rifting, heating, and stretching of the lithosphere underneath the Damara belt, followed by delamination of the subcrustal lithosphere. Hot asthenospheric material rises to take the place of the detached and sinking lithospheric base, inducing subduction and interstacking of continental crust. The much thickened continental crust is partially melted

  17. Fishes of the Taquari-Antas river basin (Patos Lagoon basin, southern Brazil

    Directory of Open Access Journals (Sweden)

    FG. Becker

    Full Text Available The aquatic habitats of the Taquari-Antas river basin (in the Patos Lagoon basin, southern Brazil are under marked environmental transformation because of river damming for hydropower production. In order to provide an information baseline on the fish fauna of the Taquari-Antas basin, we provide a comprehensive survey of fish species based on primary and secondary data. We found 5,299 valid records of fish species in the basin, representing 119 species and 519 sampling sites. There are 13 non-native species, six of which are native to other Neotropical river basins. About 24% of the total native species are still lacking a taxonomic description at the species level. Three native long-distance migratory species were recorded (Leporinus obtusidens, Prochilodus lineatus, Salminus brasiliensis, as well as two potential mid-distance migrators (Parapimelodus nigribarbis and Pimelodus pintado. Although there is only one officially endangered species in the basin (S. brasiliensis, restricted range species (21.7% of total species should be considered in conservation efforts.

  18. River-flow predictions for the South African mid-summer using a coupled general circulation model

    CSIR Research Space (South Africa)

    Olivier, C

    2013-09-01

    Full Text Available African Society for Atmospheric Sciences (SASAS) 2013 http://sasas.ukzn.ac.za/homepage.aspx 1 Tel: +27 12 367 6008 Fax: +27 12 367 6189 Email: cobus.olivier@weathersa.co.za RIVER-FLOW PREDICTIONS FOR THE SOUTH AFRICAN MID-SUMMER USING A COUPLED... for Atmospheric Sciences (SASAS) 2013 http://sasas.ukzn.ac.za/homepage.aspx 2 drops to 127 nationally and 65 stations for the area of interest. A recent coupled modeling system developed at the South African Weather Service (SAWS), that utilizes...

  19. Why is Southern African canine babesiosis so virulent? An evolutionary perspective

    Directory of Open Access Journals (Sweden)

    Penzhorn Barend L

    2011-04-01

    Full Text Available Abstract Canine babesiosis is a common, highly virulent disease in Southern Africa with even pups and juveniles being severely affected. This contrasts with bovine babesiosis, for example, where host, parasite and vector co-evolved and young animals develop immunity after infection without showing clinical signs. Babesia rossi, the main causative organism of canine babesiosis in sub-Saharan Africa, was first described from a side-striped jackal (Canis adustus in Kenya. Although data are meagre, there is evidence that indigenous African canids, such as jackals and wild dogs (Lycaon pictus, can harbour the parasite without showing untoward effects. Dogs are not indigenous to Africa. The vast majority of dogs presented at veterinary facilities in South Africa represent recently introduced European, Asian or American breeds. The contention is that B. rossi is a new challenge to which these dogs have not adapted. With intensive treatment of clinical cases, natural selection is effectively negated and the status quo will probably be maintained indefinitely. It is postulated that Babesia vogeli, which frequently results in unapparent infections or mild manifestations in dogs, represents or is closely related to the ancestral form of the canine parasite, possibly originating from wolves (Canis lupus.

  20. Regional health governance: A suggested agenda for Southern African health diplomacy.

    Science.gov (United States)

    Penfold, Erica Dale; Fourie, Pieter

    2015-12-01

    Regional organisations can effectively promote regional health diplomacy and governance through engagement with regional social policy. Regional bodies make decisions about health challenges in the region, for example, the Union of South American Nations (UNASUR) and the World Health Organisation South East Asia Regional Office (WHO-SEARO). The Southern African Development Community (SADC) has a limited health presence as a regional organisation and diplomatic partner in health governance. This article identifies how SADC facilitates and coordinates health policy, arguing that SADC has the potential to promote regional health diplomacy and governance through engagement with regional social policy. The article identifies the role of global health diplomacy and niche diplomacy in health governance. The role of SADC as a regional organisation and the way it functions is then explained, focusing on how SADC engages with health issues in the region. Recommendations are made as to how SADC can play a more decisive role as a regional organisation to implement South-South management of the regional social policy, health governance and health diplomacy agenda.

  1. Challenge in environmentally sustainable development in some southern African developing countries

    International Nuclear Information System (INIS)

    Chiburre, J.A.

    2005-01-01

    This paper examines the challenges in attaining environmentally sustainable development in some southern African developing countries, with main focus on environmentally degrading activities carried out by the poor rural communities as the only way of scaling down poverty. The typical examples include, among others, charcoal burning, firewood gathering and hunting. These activities are practiced by poor rural communities for commercial purposes, with the main market being the urban areas; whose population increase and the inability to afford electricity for domestic purposes have made the demand for charcoal and firewood to increase. While recognising the right for the basic needs for everyone, efforts have been made to reduce the pressure exerted by rural communities on to natural resources, and alternative income generating activities have been adopted. However, successes in these fields are still not observable. The paper also discusses the need for integrated approaches that might reduce the demand on natural forest resources-based energy, which consist of subsidized electricity, fast growing tree plantation, and energy efficiency, among others. (author)

  2. The African cynodont Aleodon (Cynodontia, Probainognathia in the Triassic of southern Brazil and its biostratigraphic significance.

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    Agustín G Martinelli

    Full Text Available In this contribution we report the first occurrence of the enigmatic African probainognathian genus Aleodon in the Middle-early Late Triassic of several localities from the state of Rio Grande do Sul in southern Brazil. Aleodon is unusual among early probainognathians in having transversely-expanded postcanine teeth, similar to those of gomphodont cynognathians. This genus was previously known from the Manda Beds of Tanzania and the upper Omingonde Formation of Namibia. The Brazilian record of this genus is based upon multiple specimens representing different ontogenetic stages, including three that were previously referred to the sectorial-toothed probainognathian Chiniquodon theotonicus. We propose a new species of Aleodon (A. cromptoni sp. nov. based on the specimens from Brazil. Additionally, we tentatively refer one specimen from the upper Omingonde Formation of Namibia to this new taxon, strengthening biostratigraphic correlations between these strata. Inclusion of A. cromptoni in a phylogenetic analysis of eucynodonts recovers it as the sister-taxon of A. brachyrhamphus within the family Chiniquodontidae. The discovery of numerous specimens of Aleodon among the supposedly monospecific Chiniquodon samples of Brazil raises concerns about chiniquodontid alpha taxonomy, particularly given the extremely broad geographic distribution of Chiniquodon. The discovery of Brazilian Aleodon and new records of the traversodontid Luangwa supports the hypothesis that at least two subzones can be recognized in the Dinodontosaurus Assemblage Zone.

  3. The Bible and evolution: Opinions amongst southern African clergy and theologians from the Reformed church tradition

    Directory of Open Access Journals (Sweden)

    Peet J. van Dyk

    2013-02-01

    Full Text Available The main objectives of the present study were to determine the opinions of southern African clergy and theologians (from the Reformed church tradition about evolution and faith and to assess their degree of knowledge regarding the biological theory of evolution. A total of 1720 structured electronic questionnaires were sent out via email to all clergy belonging to the �Nederduitse Gereformeerde� and �Hervormde� churches, of which 89 were received back. The SPSS 20 statistical program was used to conduct descriptive and inferential statistical analyses of these data. Most participants were positive about the theory of biological evolution, but expressed the belief that evolution should be seen as a process guided by God. However, most participants failed to appreciate the fact that this view was contrary to the non-teleological nature of the biological theory of evolution and failed to distinguish between what should be accepted in faith and what can be demonstrated or �proved� (e.g. as is common in intelligent design circles. Many participants were not clear about the finer aspects of evolutionary theory and therefore often believed common misconceptions about it. In conclusion, one could say that participants were positive about evolution and, at least nominally, agreed with non-fundamentalist views of the Bible.

  4. Southern African HIV Clinicians Society adult antiretroviral therapy guidelines: Update on when to initiate antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Graeme Meintjes

    2015-12-01

    Full Text Available The most recent version of the Southern African HIV Clinicians Society’s adult antiretroviral therapy (ART guidelines was published in December 2014. In the 27 August 2015 edition of the New England Journal of Medicine, two seminal randomised controlled trials that addressed the optimal timing of ART in HIV-infected patients with high CD4 counts were published: Strategic timing of antiretroviral therapy (START and TEMPRANO ANRS 12136 (Early antiretroviral treatment and/or early isoniazid prophylaxis against tuberculosis in HIV-infected adults. The findings of these two trials were consistent: there was significant individual clinical benefit from starting ART immediately in patients with CD4 counts higher than 500 cells/μL rather than deferring until a certain lower CD4 threshold or clinical indication was met. The findings add to prior evidence showing that ART reduces the risk of onward HIV transmission. Therefore, early ART initiation has the public health benefits of potentially reducing both HIV incidence and morbidity. Given this new and important evidence, the Society took the decision to provide a specific update on the section of the adult ART guidelines relating to when ART should be initiated.

  5. NOM characterization and removal at six Southern African water treatment plants

    Directory of Open Access Journals (Sweden)

    J. Haarhoff

    2010-04-01

    Full Text Available Organic pollution is a major concern during drinking water treatment. Major challenges attributed to organic pollution include the proliferation of pathogenic micro-organisms, prevalence of toxic and physiologically disruptive organic micro-pollutants, and quality deterioration in water distribution systems. A major component of organic pollution is natural organic matter (NOM. The operational mechanisms of most unit processes are well understood. However, their interaction with NOM is still the subject of scientific research. This paper takes the form of a meta-study to capture some of the experiences with NOM monitoring and analysis at a number of Southern African Water Treatment Plants. It is written from the perspective of practical process selection, to try and coax some pointers from the available data for the design of more detailed pilot work. NOM was tracked at six water treatment plants using dissolved organic carbon (DOC measurements. Fractionation of the DOC based on biodegradability and molecular weight distribution was done at a water treatment plant in Namibia. A third fractionation technique using ion exchange resins was used to assess the impact of ozonation on DOC. DOC measurements alone did not give much insight into NOM evolution through the treatment train. The more detailed characterization techniques showed that different unit processes preferentially remove different NOM fractions. Therefore these techniques provide better information for process design and optimisation than the DOC measurement which is routinely done during full scale operation at these water treatment plants.

  6. Ethical, legal and social issues in the context of the planning stages of the Southern African Human Genome Programme.

    Science.gov (United States)

    de Vries, Jantina; Slabbert, Melodie; Pepper, Michael S

    2012-03-01

    As the focus on the origin of modern man appears to be moving from eastern to southern Africa, it is recognised that indigenous populations in southern Africa may be the most genetically diverse on the planet and hence a valuable resource for human genetic diversity studies. In order to build regional capacity for the generation, analysis and application of genomic data, the Southern African Human Genome Programme was recently launched with the aid of seed funding from the national Department of Science and Technology in South Africa. The purpose of the article is to investigate pertinent ethical, legal and social issues that have emerged during the planning stages of the Southern African Human Genome Programme. A careful consideration of key issues such as public perception of genomic research, issues relating to genetic and genomic discrimination and stigmatisation, informed consent, privacy and data protection, and the concept of genomic sovereignty, is of paramount importance in the early stages of the Programme. This article will also consider the present legal framework governing genomic research in South Africa and will conclude with proposals regarding such a framework for the future.

  7. Emission of Volatile OrganoHalogens by Southern African Solar Salt Works

    Science.gov (United States)

    Kotte, Karsten; Weissflog, Ludwig; Lange, Christian Albert; Huber, Stefan; Pienaar, Jacobus J.

    2010-05-01

    Volatile organic compounds containing halogens - especially chlorine - have been considered for a long time of industrial origin only, and it was assumed that the production and emission of these compounds can easily be controlled by humans in case they will cause a threat for life on Earth. Since the middle of the 80ies of the last century it became clear that the biologically active organohalogens isolated by chemists are purposefully produced by nature as antibiotics or as antifeedant etc. To date more than 3800 organohalogens are known to be naturally produced by bio-geochemical processes. The global budgets of many such species are poorly understood and only now with the emergence of better analytical techniques being discovered. For example the compound chloromethane nature's production (5 GT) outdates the anthropogenic production (50 KT) by a factor of 100. Thus organohalogens are an interesting recent case in point since they can influence the ozone budget of the boundary layer, play a role in the production of aerosols and the climate change discussion. An intriguing observation is that most of the atmospheric CH3Cl and CH3Br are of terrestrial rather than of marine origin and that a number of halogenated small organic molecules are produced in soils. The high concentrations of halides in salt soils point to a possibly higher importance of natural halogenation processes as a source of volatile organohalogens. Terrestrial biota, such as fungi, plants, animals and insects, as well as marine algea, bacteria and archaea are known or suspected to be de-novo producers of volatile organohalogens. In recent years we revealed the possibility for VOX to form actively in water and bottom sediments of hyper-saline environments in the course of studying aridization processes during climatic warming. Due to the nature of their production process solar salt works, as to be found along-side the Southern African coast line but also upcountry, combine a variety of semi- and

  8. Micrandra inundata (Euphorbiaceae), a new species with unusual wood anatomy from black-water river banks in southern Venezuela

    Science.gov (United States)

    Paul E. Berry; Alex C. Wiedenhoeft

    2004-01-01

    Micrandra inundata is a distinctive new species adapted to seasonally flooded black-water river banks in southern Venezuela. Trees rarely exceed 10 m in height but have thick basal trunks composed of very lightweight wood. It has the smallest leaves and fruits of any known Micrandra species and appears to be most closely related to M. minor Benth. The botanical...

  9. Distinct responses of bacterial communities to agricultural and urban impacts in temperate southern African estuaries

    Science.gov (United States)

    Matcher, G. F.; Froneman, P. W.; Meiklejohn, I.; Dorrington, R. A.

    2018-01-01

    Worldwide, estuaries are regarded as amongst the most ecologically threatened ecosystems and are increasingly being impacted by urban development, agricultural activities and reduced freshwater inflow. In this study, we examined the influence of different human activities on the diversity and structure of bacterial communities in the water column and sediment in three distinct, temperate permanently open estuarine systems within the same geographic region of southern Africa. The Kariega system is freshwater-deprived and is considered to be relatively pristine; the Kowie estuary is marine-dominated and impacted by urban development, while the Sundays system is fresh-water dominated and impacted by agricultural activity in its catchment. The bacterial communities in all three systems comprise predominantly heterotrophic species belonging to the Bacteroidetes and Proteobacteria phyla with little overlap between bacterioplankton and benthic bacterial communities at the species level. There was overlap between the operational taxonomic units (OTUs) of the Kowie and Kariega, both marine-influenced estuaries. However, lower species richness in the Kowie, likely reflects the impact of human settlements along the estuary. The dominant OTUs in the Sundays River system were distinct from those of the Kariega and Kowie estuaries with an overall decrease in species richness and evenness. This study provides an important snapshot into the microbial population structures of permanently open temperate estuarine systems and the influence of anthropogenic impacts on bacterial diversity and community structure.

  10. Initial antimicrobial activity studies of plants of the riverside forests of the southern Uruguay River

    Directory of Open Access Journals (Sweden)

    Ana Bertucci

    Full Text Available Development of new antimicrobial compounds against different microorganisms is becoming critically important, as infectious diseases are still one of the leading causes of death in the world. Plants can be a useful source of these lead compounds. In this study, 66 extracts of 25 plants of the riverside forest of southern Uruguay River were studied for antimicrobial activity against Staphylococcus aureus, Listeria inocua, Escherichia coli, Pseudomonas aeruginosa, Mycobacterium tuberculosis, Aspergillus niger and Candida albicans. Fifty-three of these extracts showed some kind of antimicrobial activity. Six of these (Eugenia mansoni, Eugenia repanda, Myrcianthes cisplatensis, Paullinia ellegans, Petunia sp and Ruprechtia laxiflora presented activity against Mycobacterium tuberculosis with MIC values as low as 50 μg/mL.

  11. Pan-African deformations in the basement of the Negele area, southern Ethiopia

    Science.gov (United States)

    Yihunie, Tadesse

    2002-03-01

    Polydeformed and metamorphosed Neoproterozoic rocks of the East African Orogen in the Negele area constituted three lithostructurally distinct and thrust-bounded terranes. These are, from west to east, the Kenticha, Alghe and Bulbul terranes. The Kenticha and Bulbul terranes are metavolcano-sedimentary and ultramafic sequences, representing parts of the Arabian-Nubian Shield (ANS), which are welded to the central Alghe gneissic terrane of the Mozambique Belt affinity along N-S-trending sheared thrust contacts. Structural data suggest that the Negele basement had evolved through three phases of deformation. During D1 (folding) deformation, north-south upright and inclined folds with north-trending axes were developed. East and west-verging thrusts, right-lateral shearing along the north-oriented Kenticha and Bulbul thrust contacts and related structural elements were developed during D2 (thrusting) deformation. The pervasive D1 event is interpreted to have occurred at 620-610 Ma and the D2 event ended prior to 554 Ma. Right-lateral strike-slips along thrust contacts are interpreted to have been initiated during late D2. During D3, left-lateral strike-slip along the Wadera Shear Zone and respective strike-slip movements along conjugate set of shear zones were developed in the Alghe terrane, and are interpreted to have occurred later than 557 Ma. The structural data suggest that eastward thrusting of the Kenticha and westward tectonic transport of the Bulbul sequences over the Alghe gneissic terrane of the Mozambique Belt, during D2, were accompanied by right-lateral strike-slip displacements along thrust contacts. Right-lateral strike-slip movements along the Kenticha thrust contact, further suggest northward movement of the Kenticha sequence during the Pan-African orogeny in the Neoproterozoic. Left-lateral strike-slip along the orogen-parallel NNE-SSW Wadera Shear Zone and strike-slip movements along a conjugate set of shear zones completed final terrane

  12. A new Scleromystax species (Siluriformes: Callichthyidae from coastal rivers of southern Brazil

    Directory of Open Access Journals (Sweden)

    Marcelo R. Britto

    Full Text Available The recently resurrected callichthyid catfish genus Scleromystax includes species occurring in several Brazilian coastal river basins from southern Bahia to southern Santa Catarina. Several character states, especially those related to sexual dimorphism, demonstrate the monophyly of Scleromystax. Examination of Scleromystax specimens sampled from streams in the Ilha de Santa Catarina and Nova Veneza, and the rio Mampituba basin, Santa Catarina and Rio Grande do Sul States, revealed that they constitute a new taxon, and thus the southernmost record for the genus. Scleromystax salmacis, new species, has coloration similar to that of S. macropterus, differing from that species mainly by the absence of a black spot on the base of the median caudal-fin rays, and transverse blotches along the body more irregular than those in S. macropterus. In addition to differences in coloration and external and osteological characters, the new species differs from S. barbatus and S. prionotos by its more rounded snout. The new taxon is also distinguished from its congeners by the presence of a single perforated dorsolateral body plate, similar to the condition found in some Aspidoras species, orientation of the ventral keel of the scapulocoracoid, and by the absence of sexually dimorphic features.

  13. Availability of ground water in the middle Merrimack River basin, central and southern New Hampshire

    Science.gov (United States)

    Cotton, J.E.

    1976-01-01

    Sufficient amounts of water to supply single family homes are available from the bedrock aquifer nearly everywhere in the middle Merrimack River basin in central and southern New Hampshire. Relatively this and narrow, unconsolidated aquifers of sand or sand and gravel commonly capable of yielding more than 200 gallons per minute to properly located and constructed wells are found only in major stream valleys. The map provides a preliminary assessment of the availability of ground water in the basin, as determined by estimating the capability of the aquifers to store and transmit water. On the map, aquifers are rated as having high, medium, or low potential to yield water. Ground water in the middle Merrimack River basin is generally of good chemical quality. Most of it is clear and colorless, contains no suspended matter and practically no bacteria, water may be affected by land-use practices. Degradation of water quality may occur in unsewered residential and village areas, near solid-waste-disposal sites, agricultural land, and major highways. (Woodard-USGS)

  14. Systematics of the southern African genus Ixia (Iridaceae: Crocoideae: 4. Revision of sect. Dichone

    Directory of Open Access Journals (Sweden)

    P. Goldblatt

    2012-12-01

    Full Text Available The southern African genus Ixia L. comprises ± 90 species from the winter-rainfall zone of the subcontinent. Ixia sect. Dichone (Salisb. ex Baker Goldblatt & J.C.Manning, one of four sections in the genus and currently including 10 species and three varieties, is distinguished by the following floral characters: lower part of the perianth tube filiform and tightly clasping the style; filaments not decurrent; upper part of the perianth tube short to vestigial; style branches involute-tubular and stigmatic only at the tips; and so-called subdidymous anthers. We review the taxonomy of the section, providing complete descriptions and distribution maps, and a key to the species. I. amethystina Manning & Goldblatt is recognized to be a later synonym of I. brevituba G.J.Lewis. Most collections currently included under that name represent another species, here described as I. rigida. We recognize five additional species in the section: early summer-blooming I. altissima from the Cedarberg; I. bifolia from the Caledon District; I. flagellaris, a stoloniferous species from the Cedarberg; I. simulans from the western Langeberg; and I. tenuis from the Piketberg. We also raise to species rank I. micrandra var. confusa and var. minor, as I. confusa and I. minor respectively. Foliar and associated floral variation in the widespread I. scillaris has led us to recognize two new subspecies among its northern populations, broad leaved subsp. latifolia and the dwarfed, smaller flowered subsp. toximontana; subsp. scillaris is restricted to the immediate southwestern Cape, from Darling to Somerset West. Sect. Dichone now has 17 species and two subspecies.

  15. Geochemical character of Southern African Kimberlites: a new approach based on isotopic constraints

    International Nuclear Information System (INIS)

    Smith, C.B.; Gurney, J.J.; Ebrahim, N.

    1985-01-01

    Major and trace element compositions of southern African kimberlite samples previously analysed for isotopic compositions confirm that isotopically defined Group I (basaltic) and Group II (micaceous) variants have distinctive geochemical signatures. These signatures are generally consistent with geochemical variation in petrographically defined types. Stepwise discriminant function analysis is used to define the most important geochemical distinctions at the group level and to derive a procedure which successfully classifies a large number of unknowns based on chemical composition only. In comparison to Group I, Group II kimberlites have consistently higher abundances of SiO 2 , K 2 O, Pb, Rb, Ba and LREE, and lower abundances of TiO 2 and Nb. In conjunction with isotopic results, the distinctions in incompatible element contents in particular are believed to reflect broad differences in source rock character. Results are consistent with derivation of Group I kimberlites from asthenospheric-like sources similar to those from which oceanic island basalts are produced. In contrast, Group II kimberlites are inferred to originate from sources within ancient stabilized subcontinental lithosphere characterized by time-averaged incompatible element enrichment. Group I kimberlites can be further subdivided into two isotopically similar types to some degree correlative with tectonic environment. Compared to subgroup IA (on-craton), IB kimberlites have lower SiO 2 and higher CaO, FeO + Fe 2 O 3 and volatile contents in addition to somewhat greater TiO 2 , P 2 O 5 , Nb, Zr and Y abundances, and tend to occur outside the inferred boundaries of the Kaapvaal Craton though exceptions are present and new unpublished data suggest that this group may be relatively common on the craton

  16. The second Southern African Bird Atlas Project: Causes and consequences of geographical sampling bias.

    Science.gov (United States)

    Hugo, Sanet; Altwegg, Res

    2017-09-01

    Using the Southern African Bird Atlas Project (SABAP2) as a case study, we examine the possible determinants of spatial bias in volunteer sampling effort and how well such biased data represent environmental gradients across the area covered by the atlas. For each province in South Africa, we used generalized linear mixed models to determine the combination of variables that explain spatial variation in sampling effort (number of visits per 5' × 5' grid cell, or "pentad"). The explanatory variables were distance to major road and exceptional birding locations or "sampling hubs," percentage cover of protected, urban, and cultivated area, and the climate variables mean annual precipitation, winter temperatures, and summer temperatures. Further, we used the climate variables and plant biomes to define subsets of pentads representing environmental zones across South Africa, Lesotho, and Swaziland. For each environmental zone, we quantified sampling intensity, and we assessed sampling completeness with species accumulation curves fitted to the asymptotic Lomolino model. Sampling effort was highest close to sampling hubs, major roads, urban areas, and protected areas. Cultivated area and the climate variables were less important. Further, environmental zones were not evenly represented by current data and the zones varied in the amount of sampling required representing the species that are present. SABAP2 volunteers' preferences in birding locations cause spatial bias in the dataset that should be taken into account when analyzing these data. Large parts of South Africa remain underrepresented, which may restrict the kind of ecological questions that may be addressed. However, sampling bias may be improved by directing volunteers toward undersampled regions while taking into account volunteer preferences.

  17. Low flows and reservoir management for the Durance River basin (Southern France) in the 2050s

    Science.gov (United States)

    Sauquet, Eric

    2015-04-01

    The Durance River is one of the major rivers located in the Southern part of France. Water resources are under high pressure due to significant water abstractions for human uses within and out of the natural boundaries of the river basin through an extended open channel network. Water demands are related to irrigation, hydropower, drinking water, industries and more recently water management has included water needs for recreational uses as well as for preserving ecological services. Water is crucial for all these activities and for the socio-economic development of South Eastern France. Both socio-economic development and population evolution will probably modify needs for water supply, irrigation, energy consumption, tourism, industry, etc. In addition the Durance river basin will have to face climate change and its impact on water availability that may question the sustainability of the current rules for water allocation. The research project R²D²-2050 "Risk, water Resources and sustainable Development within the Durance river basin in 2050" aims at assessing future water availability and risks of water shortage in the 2050s by taking into account changes in both climate and water management. R²D²-2050 is partially funded by the French Ministry in charge of Ecology and the Rhône-Méditerranée Water Agency. This multidisciplinary project (2010-2014) involves Irstea, Electricité de France (EDF), the University Pierre et Marie Curie (Paris), LTHE (CNRS), the Société du Canal de Provence (SCP) and the research and consultancy company ACTeon. A set of models have been developed to simulate climate at regional scale (given by 330 projections obtained by applying three downscaling methods), water resources (provided by seven rainfall-runoff models forced by a subset of 330 climate projections), water demand for agriculture and drinking water, for different sub basins of the Durance River basin upstream of Mallemort under present day and under future conditions

  18. Psychometric evaluation of the Problem Areas in Diabetes (PAID survey in Southern, rural African American women with Type 2 diabetes

    Directory of Open Access Journals (Sweden)

    Elasy Tom A

    2008-02-01

    Full Text Available Abstract Background The Problem Areas in Diabetes (PAID survey is a measure of diabetes-related stress for which reported use has been in largely Caucasian populations. Our purpose was to assess the psychometric properties of the PAID in Southern rural African American women with Type 2 diabetes. Methods A convenience sample of African American women (N = 131 ranging from 21–50 years of age and diagnosed with Type 2 diabetes were recruited for a survey study from two rural Southern community health centers. Participants completed the PAID, Center for Epidemiological Studies-Depression Scale (CES-D, and the Summary of Diabetes Self-Care Activities Scale (SDSCA. Factor analysis, Cronbach's coefficient alpha, and construct validation facilitated psychometric evaluation. Results A principle component factor analysis of the PAID yielded two factors, 1 a lack of confidence subscale, and 2 a negative emotional consequences subscale. The Lack of Confidence and Negative Emotional Consequences subscales, but not the overall PAID scale, were associated with glycemic control and body mass index, respectively. Relationships with measures of depression and diabetes self-care supported construct validity of both subscales. Both subscales had acceptable (alpha = 0.85 and 0.94 internal consistency measures. Conclusion A psychometrically sound two-factor solution to the PAID survey is identified in Southern, rural African American women with Type 2 diabetes. Lack of confidence in and negative emotional consequences of diabetes self-care implementation provide a better understanding of determinants of glycemic control and weight than an aggregate of the two scales.

  19. Improve projections of changes in southern African summer rainfall through comprehensive multi-timescale empirical statistical downscaling

    Science.gov (United States)

    Dieppois, B.; Pohl, B.; Eden, J.; Crétat, J.; Rouault, M.; Keenlyside, N.; New, M. G.

    2017-12-01

    The water management community has hitherto neglected or underestimated many of the uncertainties in climate impact scenarios, in particular, uncertainties associated with decadal climate variability. Uncertainty in the state-of-the-art global climate models (GCMs) is time-scale-dependant, e.g. stronger at decadal than at interannual timescales, in response to the different parameterizations and to internal climate variability. In addition, non-stationarity in statistical downscaling is widely recognized as a key problem, in which time-scale dependency of predictors plays an important role. As with global climate modelling, therefore, the selection of downscaling methods must proceed with caution to avoid unintended consequences of over-correcting the noise in GCMs (e.g. interpreting internal climate variability as a model bias). GCM outputs from the Coupled Model Intercomparison Project 5 (CMIP5) have therefore first been selected based on their ability to reproduce southern African summer rainfall variability and their teleconnections with Pacific sea-surface temperature across the dominant timescales. In observations, southern African summer rainfall has recently been shown to exhibit significant periodicities at the interannual timescale (2-8 years), quasi-decadal (8-13 years) and inter-decadal (15-28 years) timescales, which can be interpret as the signature of ENSO, the IPO, and the PDO over the region. Most of CMIP5 GCMs underestimate southern African summer rainfall variability and their teleconnections with Pacific SSTs at these three timescales. In addition, according to a more in-depth analysis of historical and pi-control runs, this bias is might result from internal climate variability in some of the CMIP5 GCMs, suggesting potential for bias-corrected prediction based empirical statistical downscaling. A multi-timescale regression based downscaling procedure, which determines the predictors across the different timescales, has thus been used to

  20. Improving epidemic malaria planning, preparedness and response in Southern Africa. Report on the 1st Southern African Regional Epidemic Outlook Forum, Harare, Zimbabwe, 26-29 September, 2004.

    Science.gov (United States)

    DaSilva, Joaquim; Garanganga, Brad; Teveredzi, Vonai; Marx, Sabine M; Mason, Simon J; Connor, Stephen J

    2004-10-22

    following is a report on the 1st Southern African Regional Epidemic Outlook Forum, which was held in Harare, Zimbabwe, 26th-29th September, 2004.

  1. AVOIDING MAZIBUKO: WATER SECURITY AND CONSTITUTIONAL RIGHTS IN SOUTHERN AFRICAN CASE LAW

    Directory of Open Access Journals (Sweden)

    Ed Couzens

    2015-11-01

    Full Text Available The 2009 judgment by the Constitutional Court of South Africa in Mazibuko v City of Johannesburg is seen by many as a watershed in the interpretation of the fundamental constitutional right of access to water. The Constitutional Court ruled that the right of access to sufficient water does not require that the state provide every person upon demand and without more with sufficient water. Nor does the obligation confer on any person a right to claim "sufficient water" from the state immediately. Reactions to the judgment have been consistently negative, with criticisms largely focusing on the Court's apparent lack of appreciation for the situation of the very poor. It is not easy, however, to overturn a decision of the Constitutional Court and South Africa will need to work within the constraints of the precedent for many years to come. It is suggested in this article that two subsequent, recent judgments (one of the Supreme Court of Appeal in South Africa, City of Cape Town v Strümpher, 2012, and one of the High Court in Zimbabwe, Mushoriwa v City of Harare, 2014 show how it might be possible for courts to avoid the Mazibuko precedent and yet give special attention to water-related rights. Both cases concerned spoliation applications in common law, but both were decided as though access to water supply and water-related rights allow a court to give weight to factors other than the traditional grounds for a spoliation order. It can be argued that in both cases the unlawfulness necessary for a spoliation order arose from a combination of dispossession and breach of rights in respect of a very particular and special kind of property. In the arid and potentially water-stressed Southern African region, and in the context of extreme and apparently increasing poverty, there will undoubtedly be more court cases to come involving access to water. Conclusions are drawn as to how the two judgments considered might offer a way to ameliorate the harsh

  2. Rayleigh Wave Phase Velocities Beneath the Central and Southern East African Rift System

    Science.gov (United States)

    Adams, A. N.; Miller, J. C.

    2017-12-01

    This study uses the Automated Generalized Seismological Data Function (AGSDF) method to develop a model of Rayleigh wave phase velocities in the central and southern portions of the East African Rift System (EARS). These phase velocity models at periods of 20-100s lend insight into the lithospheric structures associated with surficial rifting and volcanism, as well as basement structures that pre-date and affect the course of rifting. A large dataset of >700 earthquakes is used, comprised of Mw=6.0+ events that occurred between the years 1995 and 2016. These events were recorded by a composite array of 176 stations from twelve non-contemporaneous seismic networks, each with a distinctive array geometry and station spacing. Several first-order features are resolved in this phase velocity model, confirming findings from previous studies. (1) Low velocities are observed in isolated regions along the Western Rift Branch and across the Eastern Rift Branch, corresponding to areas of active volcanism. (2) Two linear low velocity zones are imaged trending southeast and southwest from the Eastern Rift Branch in Tanzania, corresponding with areas of seismic activity and indicating possible incipient rifting. (3) High velocity regions are observed beneath both the Tanzania Craton and the Bangweulu Block. Furthermore, this model indicates several new findings. (1) High velocities beneath the Bangweulu Block extend to longer periods than those found beneath the Tanzania Craton, perhaps indicating that rifting processes have not altered the Bangweulu Block as extensively as the Tanzania Craton. (2) At long periods, the fast velocities beneath the Bangweulu Block extend eastwards beyond the surficial boundaries, to and possibly across the Malawi Rift. This may suggest the presence of older, thick blocks of lithosphere in regions where they are not exposed at the surface. (3) Finally, while the findings of this study correspond well with previous studies in regions of overlapping

  3. African languages — is the writing on the screen? | Bosch | Southern ...

    African Journals Online (AJOL)

    The trends emerging in the natural language processing (NLP) of African languages spoken in South Africa, are explored in order to determine whether research in and development of such NLP is keeping abreast of international developments. This is done by investigating the past, present and future of NLP of African ...

  4. The bi-decadal rainfall cycle, Southern Annular Mode and tropical cyclones over the Limpopo River Basin, southern Africa

    CSIR Research Space (South Africa)

    Malherbe, J

    2014-06-01

    Full Text Available contribution to rainfall by tropical cyclones and depressions. The findings suggest that a broadening of the Hadley circulation underpinned by an anomalous anticyclonic pattern to the east of southern Africa altered tropospheric steering flow, relative...

  5. The occurrence of Campylobacter in river water and waterfowl within a watershed in southern Ontario, Canada.

    Science.gov (United States)

    Van Dyke, M I; Morton, V K; McLellan, N L; Huck, P M

    2010-09-01

    Quantitative PCR and a culture method were used to investigate Campylobacter occurrence over 3 years in a watershed located in southern Ontario, Canada that is used as a source of drinking water. Direct DNA extraction from river water followed by quantitative PCR analysis detected thermophilic campylobacters at low concentrations (seagulls, ducks and geese) were detected at a similar rate using PCR (32%) and culture-based (29%) methods, and although Campylobacter jejuni was isolated most frequently, C. lari ssp. concheus was also detected. Campylobacter were frequently detected at low concentrations in the watershed. Higher prevalence rates using quantitative PCR was likely because of the formation of viable but nonculturable cells and low recovery of the culture method. In addition to animal and human waste, waterfowl can be an important contributor of Campylobacter in the environment. Results of this study show that Campylobacter in surface water can be an important vector for human disease transmission and that method selection is important in determining pathogen occurrence in a water environment. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

  6. Temporal changes of land use in Asi river delta (Hatay, Southern Turkey).

    Science.gov (United States)

    Korkmaz, Hüseyin; Cetin, Bayram; Kuscu, Veysel; Ege, Ismail; Bom, Ahmet; Ozsahin, Emre; Karatas, Atilla

    2012-04-01

    Increasing non-ecological land use necessitates more efficient using and utilization of land by man. Therefore, in recent years studies on sustainable land use have gained momentum. In this study, temporal change in land use, mainly between years 1940 and 2010, in Asi river delta on Southern Turkey was covered. To this end, in addition to literature, topographical maps and satellite images from year 1940 and after were used. Also, data were collected through field studies and interviews. Collected data were evaluated from geographical viewpoint using Geographical information system (GIS) and Remote sensing (RS) methods. Unplanned settlement in delta has reached levels high enough to threaten agricultural fields. Especially, greattendencyshown by Samandag city and the villages around it towards expanding into delta is an indicatorof this threat In additon, uncontrolled sand mining and touristic facilities on the coastline are also indicators of wrong land use. In future, direction of settlement to slopes around the delta rather than lowlands will be a much more ecological approach.

  7. Soil erosion vulnerability in the verde river basin, southern minas gerais

    Directory of Open Access Journals (Sweden)

    Vinícius Augusto de Oliveira

    2014-06-01

    Full Text Available Soil erosion is one of the most significant environmental degradation processes. Mapping and assessment of soil erosion vulnerability is an important tool for planning and management of the natural resources. The objective of the present study was to apply the Revised Universal Soil Loss Equation (RUSLE using GIS tools to the Verde River Basin (VRB, southern Minas Gerais, in order to assess soil erosion vulnerability. A annual rainfall erosivity map was derived from the geographical model adjusted for Southeastern Brazil, calculating an annual value for each pixel. The maps of soil erodibility (K, topographic factor (LS, and use and management of soils (C were developed from soils and their uses map and the digital elevation model (DEM developed for the basin. In a GIS environment, the layers of the factors were combined to create the soil erosion vulnerability map according to RUSLE. The results showed that, in general, the soils of the VRB present a very high vulnerability to water erosion, with 58.68% of soil losses classified as "High" and "Extremely High" classes. In the headwater region of VRB, the predominant classes were "Very High" and "Extremely High" where there is predominance of Cambisols associated with extensive pastures. Furthermore, the integration of RUSLE/GIS showed an efficient tool for spatial characterization of soil erosion vulnerability in this important basin of the Minas Gerais state.

  8. Invasive, naturalized and casual alien plants in southern Africa: a sum­mary based on the Southern African Plant Invaders Atlas (SAPIA

    Directory of Open Access Journals (Sweden)

    L. Henderson

    2007-08-01

    Full Text Available The primary objective of this publication is to provide an overview of the species identity, invasion status, geographical extent, and abundance of alien plants in South Africa, Swaziland and Lesotho, based on field records from 1979 to the end of 2000. The dataset is all the species records for the study area in the Southern African Plant Invaders Atlas (SAPIA database during this time period. A total of 548 naturalized and casual alien plant species were catalogued and invasion was recorded almost throughout the study area. Most invasion, in terms of both species numbers and total species abundance, was recorded along the southern, southwestern and eastern coastal belts and in the adjacent interior. This area includes the whole of the Fynbos and Forest Biomes, and the moister eastern parts of the Grassland and Savanna Biomes. This study reinforces previous studies that the Fynbos Biome is the most extensively invaded vegetation type in South Africa but it also shows that parts of Savanna and Grassland are as heavily invaded as parts of the Fynbos. The Fabaceae is prominent in all biomes and Acacia with 17 listed species, accounts for a very large proportion of all invasion. Acacia mearmii was by far the most prominent invasive species in the study area, followed by A. saligna, Lantana camara, A. cyclops, Opuntia ficus-indica. Solarium mauritianum, Populus alba/xcanescens, Melia azedarach, A. dealbata and species of Prosopis.

  9. Fourier analysis of temporal NDVI in the Southern African and American continents

    NARCIS (Netherlands)

    Azzali, S.; Menenti, M.

    1996-01-01

    Results of applying Fourier analysis of temporal NDVI in southern Africa and southern America are summarized. The decomposition of complex time series of images in simpler periodic components by Fourier analysis allowed the factors that affect the vegetation cover to be analysed much easier. The

  10. THE PARADOX OF MIGRATION AND THE INTERESTS OF THE ATOMISTIC NATION-STATES: THE SOUTHERN AFRICAN PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Phazha Jimmy Ngandwe

    2013-04-01

    Full Text Available The "paradox of migration and the interests of the atomistic nation-states" interrogates the phenomenon of migration in general and in the Southern African Development Community in particular. The point of departure of the paper is the African Union and the Southern African Development Community’s legal framework on migration, as read with the national legal instruments of the different member states. Its focal point is the raison d’être of this phenomenon of migration and the corresponding approaches and attitudes of the nation-states within which migration takes place inter se. This includes the psycho-social impact of migration. Internationally as well as regionally, States are concerned with issues of sovereignty, the preservation of the welfare of the citizenry, ensuring social cohesion social, cultural and economic development including job creation, and fighting against transnational organised crime, including terrorism. The theme of the paper is that whereas migration should form the bedrock of regionalism and globalisation, the negative attitudes of the nation-states to migration are more often than not at variance with the objectives of regionalism and globalisation. The central question of the research is how states can discharge their duties and obligations vis-à-vis their nationals without perpetuating the bottlenecks to and the stigma that attaches to migration and thereby upsetting the international as well as regional integration objectives of the free movement of people. This is the issue that the paper is intended to explore. The main areas of concern are that the negative attitudes of the nation-states are manifested in the hostile treatment of migrants at all ports of entry, including illegal or ungazetted points of entry, within the nation-states in general, and in their labour markets in particular. This research therefore explores the paradoxical nature of the duties and responsibilities of states within the

  11. Morphological analysis of Trichomycterus areolatus Valenciennes, 1846 from southern Chilean rivers using a truss-based system (Siluriformes, Trichomycteridae

    Directory of Open Access Journals (Sweden)

    Nelson Colihueque

    2017-09-01

    Full Text Available Trichomycterus areolatus Valenciennes, 1846 is a small endemic catfish inhabiting the Andean river basins of Chile. In this study, the morphological variability of three T. areolatus populations, collected in two river basins from southern Chile, was assessed with multivariate analyses, including principal component analysis (PCA and discriminant function analysis (DFA. It is hypothesized that populations must segregate morphologically from each other based on the river basin that they were sampled from, since each basin presents relatively particular hydrological characteristics. Significant morphological differences among the three populations were found with PCA (ANOSIM test, r = 0.552, p < 0.0001 and DFA (Wilks’s λ = 0.036, p < 0.01. PCA accounted for a total variation of 56.16% by the first two principal components. The first Principal Component (PC1 and PC2 explained 34.72 and 21.44% of the total variation, respectively. The scatter-plot of the first two discriminant functions (DF1 on DF2 also validated the existence of three different populations. In group classification using DFA, 93.3% of the specimens were correctly-classified into their original populations. Of the total of 22 transformed truss measurements, 17 exhibited highly significant (p < 0.01 differences among populations. The data support the existence of T. areolatus morphological variation across different rivers in southern Chile, likely reflecting the geographic isolation underlying population structure of the species.

  12. Promoting transdisciplinarity in the Southern African Development Community’s water sector

    CSIR Research Space (South Africa)

    Jacobs-Mata, Inga M

    2010-09-01

    Full Text Available . Graph 2 indicates the percentage of environmental courses offered in social science degrees (political Science, International relations, Sociology, Anthropology and philosophy) in three major South African universities. The data...

  13. Southern African Journal of HIV Medicine - Vol 10, No 1 (2009)

    African Journals Online (AJOL)

    The role of concurrent sexual relationships in the spread of sexually transmitted infections in young South Africans · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. C Kenyon, M Badri ...

  14. Impact of farm dams on river flows; A case study in the Limpopo River basin, Southern Africa

    NARCIS (Netherlands)

    Meijer, E.; Querner, E.P.; Boesveld, H.

    2013-01-01

    The study analysed the impact of a farm dam on the river flow in the Limpopo River basin. Two methods are used to calculate the water inflow: one uses the runoff component from the catchment water balance; the other uses the drainage output of the SIMFLOW model. The impact on the flow in a

  15. Recent coarsening of sediments on the southern Yangtze subaqueous delta front: A response to river damming

    Science.gov (United States)

    Yang, H. F.; Yang, S. L.; Meng, Y.; Xu, K. H.; Luo, X. X.; Wu, C. S.; Shi, B. W.

    2018-03-01

    After more than 50,000 dams were built in the Yangtze basin, especially the Three Gorges Dam (TGD) in 2003, the sediment discharge to the East China Sea decreased from 470 Mt/yr before dams to the current level of 140 Mt/yr. The delta sediment's response to this decline has interested many researchers. Based on a dataset of repeated samplings at 44 stations in this study, we compared the surficial sediment grain sizes in the southern Yangtze subaqueous delta front for two periods: pre-TGD (1982) and post-TGD (2012). External factors of the Yangtze River, including water discharge, sediment discharge and suspended sediment grain size, were analysed, as well as wind speed, tidal range and wave height of the coastal ocean. We found that the average median size of the sediments in the delta front coarsened from 8.0 μm in 1982 to 15.4 μm in 2012. This coarsening was accompanied by a decrease of clay components, better sorting and more positive skewness. Moreover, the delta morphology in the study area changed from an overall accretion of 1.0 cm/yr to an erosion of - 0.6 cm/yr. At the same time, the riverine sediment discharge decreased by 70%, and the riverine suspended sediment grain size increased from 8.4 μm to 10.5 μm. The annual wind speed and wave height slightly increased by 2% and 3%, respectively, and the tidal range showed no change trend. Considering the increased wind speed and wave height, there was no evidence that the capability of the China Coastal Current to transport sediment southward has declined in recent years. The sediment coarsening in the Yangtze delta front was thus mainly attributed to the delta's transition from accumulation to erosion which was originally generated by river damming. These findings have important implications for sediment change in many large deltaic systems due to worldwide human impacts.

  16. Addressing the Issue of Gender Equity in the Presidency of the University System in the Southern African Development Community (SADC) Region

    Science.gov (United States)

    Guramatunhu-Mudiwa, Precious

    2010-01-01

    The Southern African Development Community (SADC) is a regional economic grouping of 15 countries whose common vision is to promote economic, social and political development and growth. Arguably, sustainable growth can be realized if there is equal access to all positions of power and influence in the area, but an investigation of 117…

  17. Techniques of remote sensing and GIS as tools for visualizing impact of climate change-induced flood in the southern African region.

    Science.gov (United States)

    This study employs remote sensing and Geographical Information Systems (GIS) data to visualize the impact of climate change caused by flooding in the Southern African region in order to assist decision makers’ plans for future occurrences. In pursuit of this objective, this study uses Digital Elevat...

  18. Non-uniform splitting of a single mantle plume by double cratonic roots : Insight into the origin of the central and southern East African Rift System

    NARCIS (Netherlands)

    Koptev, Alexander; Cloetingh, Sierd; Gerya, Taras; Calais, Eric; Leroy, Sylvie

    Using numerical thermo-mechanical experiments we analyse the role of an active mantle plume and pre-existing lithospheric thickness differences in the structural development of the central and southern East African Rift system. The plume-lithosphere interaction model setup captures the essential

  19. Metal levels in southern leopard frogs from the Savannah River Site: location and body compartment effects.

    Science.gov (United States)

    Burger, J; Snodgrass, J

    2001-06-01

    Tadpoles have been proposed as useful bioindicators of environmental contamination; yet, recently it has been shown that metal levels vary in different body compartments of tadpoles. Metals levels are higher in the digestive tract of bullfrog (Rana catesbeiana) tadpoles, which is usually not removed during such analysis. In this paper we examine the heavy metal levels in southern leopard frog (R. utricularia) tadpoles from several wetlands at the Savannah River Site and test the null hypotheses that (1) there are no differences in metal levels in different body compartments of the tadpoles, including the digestive tract; (2) there are no differences in heavy metal levels among different wetlands; and (3) there are no differences in the ratio of metals in the tail/body and in the digestive tract/body as a function of metal or developmental stage as indicated by body weight. Variations in heavy metal levels were explained by wetland and body compartment for all metals and by tadpole weight for selenium and manganese. In all cases, levels of metals were higher in the digestive tract than in the body or tail of tadpoles. Metal levels were highest in a wetland that had been remediated and lowest in a wetland that was never a pasture or remediated (i.e., was truly undisturbed). Although tadpoles are sometimes eaten by fish and other aquatic predators, leopard frogs usually avoid laying their eggs in ponds with such predators. However, avian predators will eat them. These data suggest that tadpoles can be used as bioindicators of differences in metal levels among wetlands and as indicators of potential exposure for higher-trophic-level organisms, but that to assess effects on the tadpoles themselves, digestive tracts should be removed before analysis. Copyright 2001 Academic Press.

  20. Diatom species composition of the Nišava river and its tributaries Jerma and Temska rivers (southern Serbia

    Directory of Open Access Journals (Sweden)

    Andrejić Jelena Z.

    2012-01-01

    Full Text Available The main objective of this paper is to report the diatom taxa identified from the Nišava River and its tributaries, the Jerma and Temska rivers. The study area included 11 sampling sites along the Nišava River, with one site on the Jerma River and one on the Temska River. Monthly samples (from stones, sediments and macrophytes were collected from May 2008 to May 2009. Diatom frustules were cleaned with chemical agents, and mounted on permanent slides. In total, 194 diatom taxa were identified. The most species rich genera are Navicula (25, Nitzschia (17 and Gomphonema (13, while other genera are presented with one or more species. Detailed floristic analysis of the benthic diatom flora has not been conducted before on these rivers. Therefore, this paper provides a baseline for future research. [Acknowledgments. The work was supported by projects Nos. TR037009, III43002 and III45012 that are financed by the Ministry of Education and Science of the Republic of Serbia.

  1. The Effects of Urbanization and Flood Control on Sediment Discharge of a Southern California River, Evidence of a Dilution Effect

    Science.gov (United States)

    Warrick, J. A.; Orzech, K. M.; Rubin, D. M.

    2004-12-01

    The southern California landscape has undergone dramatic urbanization and population growth during the past 60 years and currently supports almost 20 million inhabitants. During this time, rivers of the region have been altered with damming, channel straightening and hardening, and water transfer engineering. These changes have drastically altered water and sediment discharge from most of the region's drainage basins. Here we focus on changes in sediment discharge from the largest watershed of southern California, the Santa Ana River. Order-of-magnitude drops in the suspended sediment rating curves (the relationship between suspended sediment concentration and instantaneous river discharge) are observed between 1967 and 2001, long after the construction of a major flood control dam in 1941. These sediment concentration decreases do not, however, represent alteration of the total sediment flux from the basin (a common interpretation of sediment rating curves), but rather a dilution of suspended sediment by increases (approx. 4x) in stormwater discharge associated with urbanization. Increases in peak and total stormwater discharge are consistent with runoff patterns from urbanizing landscapes, supporting our hypothesis that the diluting water originated from stormwater runoff generated in urban areas both up- and downstream of dams. Our dilution hypothesis is further supported with water and sediment budgets, dilution calculations, and suspended and bed grain size information.

  2. Environmental risk assessment in five rivers of Parana River basin, Southern Brazil, through biomarkers in Astyanax spp.

    Science.gov (United States)

    Barros, Ivaldete Tijolin; Ceccon, Juliana Parolin; Glinski, Andressa; Liebel, Samuel; Grötzner, Sonia Regina; Randi, Marco Antonio Ferreira; Benedito, Evanilde; Ortolani-Machado, Claudia Feijó; Filipak Neto, Francisco; de Oliveira Ribeiro, Ciro Alberto

    2017-07-01

    In the current study, water quality of five river sites in Parana River basin (Brazil), utilized for public water supply, was assessed through a set of biomarkers in fish Astyanax spp. Population growth and inadequate use of land are challenges to the preservation of biodiversity and resources such as water. Some physicochemical parameters as well as somatic indexes, gills and liver histopathology, genotoxicity, and biochemical biomarkers were evaluated. The highest gonadosomatic index (GSI) and antioxidant parameters (catalase and glutathione S-transferase activities, non-protein thiols), as well as the lowest damage to biomolecules (lipid peroxidation, protein carbonylation, DNA damage) were observed in site 0 (Piava River), which is located at an environmental protected area. Site 1, located in the same river, but downstream site 0 and outside the protection area, presents some level of impact. Fish from site 2 (Antas River), which lack of riparian forest and suffer from silting, presented the highest micronucleus incidence and no melanomacrophages. Differently, individuals from site 3 (Xambrê River) and site 4 (Pinhalzinho River) which receive surface runoff from Umuarama city, urban and industrial sewage, have the highest incidences of liver and gill histopathological alterations, including neoplasia, which indicated the worst health conditions of all sites. In particular, site 4 had high levels of total nitrogen and ammonia, high turbidity, and very low oxygen levels, which indicate important chemical impact. Comparison of the biomarkers in fish allowed classification of the five sites in terms of environmental impact and revealed that sites 3 and 4 had particular poor water quality.

  3. Reconnaissance of the Manistee River, a cold-water river in the northwestern part of Michigan's Southern Peninsula

    Science.gov (United States)

    Hendrickson, G.E.; Doonan, C.J.

    1972-01-01

    The cold-water streams of the northern states provide unique recreational values to the American people (wilderness or semi-wilderness atmosphere, fast-water canoeing, trout fishing), but expanding recreational needs must be balanced against the growing demand of water for public and industrial supplies, irrigation, and dilution of sewage and other wastes. In order to make intelligent decisions regarding use and management of water resources for recreation and other demands, an analysis of hydrologic factors related to recreation is essential.The Manistee River is one of Michigan's well-known trout streams-a stream having numerous public access sites and campgrounds. Upstream from Cameron Bridge (see location map) the Manistee is rated as a first-class trout stream but below Cameron Bridge the river is rated only as a fair trout stream by the Michigan Department of Natural Resources. As a Michigan canoe trail it is second only to the Au Sable River in popularity. Esthetically, the Manistee is one of Michigan's most attractive rivers, its waters flowing cool and clean, and around each bend a pleasant wilderness scene. This report deals with that part of the river upstream from State Highway M-66 at Smithville. Several hard-surface roads give access to the upper river as shown on the location map. Numerous dirt roads and trails give access to the river at intermediate points. The recreational values of the Manistee depend on its characteristics of streamflow, water quality, and bed and banks. This atlas describes these characteristics and shows how they relate to recreational use.Much of the information presented here was obtained from basic records of the U.S. Geological Survey's Water Resources Division. Additional information was obtained from field reconnaissance surveys in 1968 and 1969. The study was made in cooperation with the Michigan Geological Survey, Gerald E. Eddy, Chief. Assistance was also obtained from other sections of the Michigan Department of

  4. Book Review | Lupton-Smith | Southern African Journal of Critical Care

    African Journals Online (AJOL)

    Cardiopulmonary Physiotherapy in Trauma: An Evidence-based Approach Edited by Heleen van Aswegen and Brenda Morrow. London: Imperial College Press, 2015. ISBN 978-1-78326-651-7. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African ...

  5. Southern African Journal of Critical Care - Vol 22, No 1 (2006)

    African Journals Online (AJOL)

    Outcome evaluation of a South African ICU - a baseline study · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. SD Hanekom, A Coetzee, M Faure, 14-20. Achievements in emergency medical care service, North-West province, 2002 -2004 · EMAIL FREE FULL TEXT ...

  6. Isotopic signature of Pan-African rejuvenation in the Kerala Khondalite belt, southern India: implications for east Gondwana reassembly

    International Nuclear Information System (INIS)

    Unnikrishnan Warrier, C.

    1997-01-01

    Sm-Nd isotope systematics on mineral separates from sillimanite-and cordierite-bearing metapelite (khondalite), and garnet-and biotite-bearing gneiss (leptynite) from the Kerala Khondalite Belt (KKB), southern India, yielded mineral isochron ages (wr-feld-bio-gar) of 537±27 Ma (MSWD=0.9) and 534±26 Ma (MSWD=1.23) respectively. Rb-Sr systematics in the same samples gave wr-feld-bio mineral isochron ages of 437±9 Ma (MSWD=0.67) and 467±9 Ma (MSWD=0.76). These results provide the first mineral isochron ages for the regional metasedimentaries in the KKB. The ε (Nd T) values at 550 Ma for khondalite and leptynite are -22.7 and -21.8 respectively. These results demonstrate a complete rejuvenation of the crust during Pan-African times. Coeval alkaline plutons emplaced along fault-lineaments in this area suggest an extensional tectonic regime. Geochronologic correlations with the Lutzow-Holm bay complexes in east Antarctica, and the highland and southwestern complex of Sri Lanka show that a similar Pan-African tectono-thermal event manifested in all the east Gondwana crustal fragments. (author)

  7. Computational analysis of candidate disease genes and variants for Salt-sensitive hypertension in indigenous Southern Africans

    KAUST Repository

    Tiffin, Nicki

    2010-09-27

    Multiple factors underlie susceptibility to essential hypertension, including a significant genetic and ethnic component, and environmental effects. Blood pressure response of hypertensive individuals to salt is heterogeneous, but salt sensitivity appears more prevalent in people of indigenous African origin. The underlying genetics of salt-sensitive hypertension, however, are poorly understood. In this study, computational methods including text- and data-mining have been used to select and prioritize candidate aetiological genes for salt-sensitive hypertension. Additionally, we have compared allele frequencies and copy number variation for single nucleotide polymorphisms in candidate genes between indigenous Southern African and Caucasian populations, with the aim of identifying candidate genes with significant variability between the population groups: identifying genetic variability between population groups can exploit ethnic differences in disease prevalence to aid with prioritisation of good candidate genes. Our top-ranking candidate genes include parathyroid hormone precursor (PTH) and type-1angiotensin II receptor (AGTR1). We propose that the candidate genes identified in this study warrant further investigation as potential aetiological genes for salt-sensitive hypertension. © 2010 Tiffin et al.

  8. A multi-centre evaluation of oral cancer in Southern and Western Nigeria: an African oral pathology research consortium initiative.

    Science.gov (United States)

    Omitola, Olufemi Gbenga; Soyele, Olujide Oladele; Sigbeku, Opeyemi; Okoh, Dickson; Akinshipo, Abdulwarith Olaitan; Butali, Azeez; Adeola, Henry Ademola

    2017-01-01

    Oral cancer is a leading cause of cancer deaths among African populations. Lack of standard cancer registries and under-reporting has inaccurately depicted its magnitude in Nigeria. Development of multi-centre collaborative oral pathology networks such as the African Oral Pathology Research Consortium (AOPRC) facilitates skill and expertise exchange and fosters a robust and systematic investigation of oral diseases across Africa. In this descriptive cross-sectional study, we have leveraged the auspices of the AOPRC to examine the burden of oral cancer in Nigeria, using a multi-centre approach. Data from 4 major tertiary health institutions in Western and Southern Nigeria was generated using a standardized data extraction format and analysed using the SPSS data analysis software (version 20.0; SPSS Inc. Chicago, IL). Of the 162 cases examined across the 4 centres, we observed that oral squamous cell carcinomas (OSCC) occurred mostly in the 6 th and 7 th decades of life and maxillary were more frequent than mandibular OSCC lesions. Regional variations were observed both for location, age group and gender distribution. Significant regional differences was found between poorly, moderately and well differentiated OSCC (p value = 0.0071). A multi-centre collaborative oral pathology research approach is an effective way to achieve better insight into the patterns and distribution of various oral diseases in men of African descent. The wider outlook for AOPRC is to employ similar approaches to drive intensive oral pathology research targeted at addressing the current morbidity and mortality of various oral diseases across Africa.

  9. Southern African ancient genomes estimate modern human divergence to 350,000 to 260,000 years ago.

    Science.gov (United States)

    Schlebusch, Carina M; Malmström, Helena; Günther, Torsten; Sjödin, Per; Coutinho, Alexandra; Edlund, Hanna; Munters, Arielle R; Vicente, Mário; Steyn, Maryna; Soodyall, Himla; Lombard, Marlize; Jakobsson, Mattias

    2017-11-03

    Southern Africa is consistently placed as a potential region for the evolution of Homo sapiens We present genome sequences, up to 13x coverage, from seven ancient individuals from KwaZulu-Natal, South Africa. The remains of three Stone Age hunter-gatherers (about 2000 years old) were genetically similar to current-day southern San groups, and those of four Iron Age farmers (300 to 500 years old) were genetically similar to present-day Bantu-language speakers. We estimate that all modern-day Khoe-San groups have been influenced by 9 to 30% genetic admixture from East Africans/Eurasians. Using traditional and new approaches, we estimate the first modern human population divergence time to between 350,000 and 260,000 years ago. This estimate increases the deepest divergence among modern humans, coinciding with anatomical developments of archaic humans into modern humans, as represented in the local fossil record. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  10. Challenges of transfrontier conservation areas: Natural resources nationalism, security and regionalism in the southern African development community region

    Directory of Open Access Journals (Sweden)

    Oswell Rusinga

    2012-12-01

    Full Text Available Transfrontier Conservation Areas (TFCAs initiatives in the Southern African Development Community (SADC region offer hope for providing a mechanism for resolving political tensions and conflicts which are not only related to environmental issues but to security concerns as well. The geopolitical implications of TFCAs in the SADC region cannot be overemphasised with regard to international relations and regional integration. The SADS region is characterised by histories of contested military balance of power and geopolitical rivalries which have a potential to degenerate into military confrontation. Although there is a strong belief in multilateral co-operation among SADC member countries, most of them often engage the international community at the bilateral level. Moreover, there is disharmony in constitutional applications of the rule of law, respect of human rights and good governance. However, TFCAs initiatives in Southern Africa have been seen as offering an opportunity to heal the wounds of pre- and post-independence wars of destabilisation through the encouragement of inter-state collaboration and co-operation by giving governments an opportunity for mutual action on issues of common interest.

  11. Future ecosystem services in a Southern African river basin: a scenario planning approach to uncertainty

    CSIR Research Space (South Africa)

    Bohensky, EL

    2006-08-01

    Full Text Available and the economy are strong and civil society plays a minor role. Fortress world is a scenario about a collapse of national governance struc- tures, a faltering economy, and a fragmented civil soci- ety. In local resources, a strong, self-reliant civil society..., between ecosystem ser- vices and biodiversity are a major conservation concern. The maintenance of some services, such as nature-based tourism, medicinal plants, and crop pollination, has a clear link to biodiversity and provides a strong economic...

  12. The roles of spirituality in the relationship between traumatic life events, mental health, and drug use among African American women from one southern state.

    Science.gov (United States)

    Staton-Tindall, Michele; Duvall, Jamieson; Stevens-Watkins, Danelle; Oser, Carrie B

    2013-09-01

    This study examines the role of spirituality as a moderator of the relationship between traumatic life experiences, mental health, and drug use in a sample of African American women. It was hypothesized that there would be an inverse relationship overall between spirituality and mental health and drug use among this sample of African American women. Secondly, was expected that spirituality would moderate the relationship between traumatic life events and mental health and drug use. African American women (n = 206) were recruited from the community and from probation officers in three urban areas of a southern state, and face-to-face interviews were completed. Findings indicated that there was a main effect for spirituality (as measured by existential well-being on the Spiritual Well-Being Scale) and traumatic life events, mental health, and alcohol use. In addition, spirituality was a significant moderator of the relationship between traumatic life events and cocaine use. Discussion and implications for African American women are included.

  13. Regional disaster risk management strategies for food security: Probing Southern African Development Community channels for influencing national policy

    Directory of Open Access Journals (Sweden)

    Happy M. Tirivangasi

    2018-05-01

    Full Text Available Natural disasters and food insecurity are directly interconnected. Climate change related hazards such as floods, hurricanes, tsunamis, droughts and other risks can weaken food security and severely impact agricultural activities. Consequently, this has an impact on market access, trade, food supply, reduced income, increased food prices, decreased farm income and employment. Natural disasters create poverty, which in turn increases the prevalence of food insecurity and malnutrition. It is clear that disasters put food security at risk. The poorest people in the community are affected by food insecurity and disasters; hence, there is a need to be prepared as well as be in a position to manage disasters. Without serious efforts to address them, the risks of disasters will become an increasingly serious obstacle to sustainable development and the achievement of sustainable development goals, particularly goal number 2 ‘end hunger, achieve food security and improved nutrition and promote sustainable agriculture’. In recent years, countries in southern Africa have experienced an increase in the frequency, magnitude and impact of climate change–related hazards such as droughts, veld fire, depleting water resources and flood events. This research aims to reveal Southern African Development Community disaster risk management strategies for food security to see how they an influence and shape policy at the national level in southern Africa. Sustainable Livelihood approach was adopted as the main theoretical framework for the study. The qualitative Analysis is based largely on data from databases such as national reports, regional reports and empirical findings on the disaster management–sustainable development nexus.

  14. Identifying sources of acidity and spatial distribution of acid sulfate soils in the Anglesea River catchment, southern Australia

    Science.gov (United States)

    Wong, Vanessa; Yau, Chin; Kennedy, David

    2015-04-01

    Globally, coastal and estuarine floodplains are frequently underlain by sulfidic sediments. When exposed to oxygen, sulfidic sediments oxidise to form acid sulfate soils, adversely impacting on floodplain health and adjacent aquatic ecoystems. In eastern Australia, our understanding of the formation of these coastal and estuarine floodplains, and hence, spatial distribution of acid sulfate soils, is relatively well established. These soils have largely formed as a result of sedimentation of coastal river valleys approximately 6000 years BP when sea levels were one to two metres higher. However, our understanding of the evolution of estuarine systems and acid sulfate soil formation, and hence, distribution, in southern Australia remains limited. The Anglesea River, in southern Australia, is subjected to frequent episodes of poor water quality and low pH resulting in closure of the river and, in extreme cases, large fish kill events. This region is heavily reliant on tourism and host to a number of iconic features, including the Great Ocean Road and Twelve Apostles. Poor water quality has been linked to acid leakage from mining activities and Tertiary-aged coal seams, peat swamps and acid sulfate soils in the region. However, our understanding of the sources of acidity and distribution of acid sulfate soils in this region remains poor. In this study, four sites on the Anglesea River floodplain were sampled, representative of the main vegetation communities. Peat swamps and intertidal marshes were both significant sources of acidity on the floodplain in the lower catchment. However, acid neutralising capacity provided by carbonate sands suggests that there are additional sources of acidity higher in the catchment. This pilot study has highlighted the complexity in the links between the floodplain, upper catchment and waterways with further research required to understand these links for targeted acid management strategies.

  15. Setting the agenda in emergency medicine in the southern African region: Conference assumptions and recommendations, Emergency Medicine Conference 2014: Gaborone, Botswana

    Directory of Open Access Journals (Sweden)

    Lloyd D. Christopher

    2014-09-01

    Full Text Available The first international emergency medicine (EM conference in Botswana was held on 15th and 16th May 2014 at the Gaborone International Convention Centre. The support from key stakeholders positioned the conference, from its conception, to deliver expert guidance on emergency medicine relevance, education and systems implementation. The conference theme was aptly: “Setting the Agenda in Emergency Medicine in the Southern African Region.” Over 300 local, regional and international delegates convened to participate in this landmark event. Country representation included Botswana, South Africa, Zambia, Namibia, Zimbabwe, Swaziland, Lesotho, Nigeria and the United States of America. Conference assumptions intersected emergency care, African burden of injury and illness and the role of the state; the public protection ethic of emergency care, and the developmental, economic and health interest in promoting EM. The recommendations addressed emergency care relevance; health systems research as an imperative for emergency systems development in southern Africa; community agency as a requisite for emergency care resilience; emergency care workers as pivotal to the emergency medical system, and support of EM system implementation. The conference recommendations – by way of setting an agenda, augur well for emergency care development and implementation in the southern African region and are likely to prove useful to the southern African countries seeking to address health service quality, EM advocacy support and implementation guidance. Emergency medicine is the only discipline with ‘universality’ and ‘responsivity’ at the point of need. This implies the widespread potential for facilitation of access to health care: a public health goal nuanced by the African development agenda.

  16. African Journal of Aquatic Science - Vol 38 (2013)

    African Journals Online (AJOL)

    Mitochondrial and nuclear DNA reveals a complete lineage sorti ng of Glossogobius callidus (Teleostei: Gobiidae) in southern Africa · EMAIL FULL TEXT ... Determining the minimum effective dose of rotenone for eradication of alien smallmouth bass Micropterus dolomieu from a South African river · EMAIL FULL TEXT ...

  17. Simulation of Regional Ground-Water Flow in the Suwannee River Basin, Northern Florida and Southern Georgia

    Science.gov (United States)

    Planert, Michael

    2007-01-01

    The Suwannee River Basin covers a total of nearly 9,950 square miles in north-central Florida and southern Georgia. In Florida, the Suwannee River Basin accounts for 4,250 square miles of north-central Florida. Evaluating the impacts of increased development in the Suwannee River Basin requires a quantitative understanding of the boundary conditions, hydrogeologic framework and hydraulic properties of the Floridan aquifer system, and the dynamics of water exchanges between the Suwannee River and its tributaries and the Floridan aquifer system. Major rivers within the Suwannee River Basin are the Suwannee, Santa Fe, Alapaha, and Withlacoochee. Four rivers west of the Suwannee River are the Aucilla, the Econfina, the Fenholloway, and the Steinhatchee; all drain to the Gulf of Mexico. Perhaps the most notable aspect of the surface-water hydrology of the study area is that large areas east of the Suwannee River are devoid of channelized, surface drainage; consequently, most of the drainage occurs through the subsurface. The ground-water flow system underlying the study area plays a critical role in the overall hydrology of this region of Florida because of the dominance of subsurface drain-age, and because ground-water flow sustains the flow of the rivers and springs. Three principal hydrogeologic units are present in the study area: the surficial aquifer system, the intermediate aquifer system, and the Floridan aquifer system. The surficial aquifer system principally consists of unconsoli-dated to poorly indurated siliciclastic deposits. The intermediate aquifer system, which contains the intermediate confining unit, lies below the surficial aquifer system (where present), and generally consists of fine-grained, uncon-solidated deposits of quartz sand, silt, and clay with interbedded limestone of Miocene age. Regionally, the intermediate aquifer system and intermediate con-fining unit act as a confining unit that restricts the exchange of water between the over

  18. Characterization of water quality for streams in the southern Yampa River basin, northwestern Colorado. Water Resources Investigation

    International Nuclear Information System (INIS)

    Parker, R.S.

    1991-01-01

    Historically, the Yampa River basin in northwestern Colorado has been an area of coal-mining development. Coal mining generally has been developed in the southern part of the basin and at lower elevations. The purpose of the report is to characterize the stream water quality by summarizing selected major dissolved constituents for the streams that drain the southern part of the Yampa River basin. Characterization is done initially by providing a statistical summary of the constituents for individual water-quality sites in the study area. These statistical summaries can be used to help assess water-quality within specified stream reaches. Water-quality data are available for sites on most perennial streams in the study area, and these data provide the best information about the immediate stream reach. Water-quality data from all sites are combined into regions, and linear-regression equations between dissolved constituents and specific conductance are calculated. Such equations provide an estimate of the water-quality relations within these regions. The equations also indicate an increase in error as individual sites are combined

  19. The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa

    Directory of Open Access Journals (Sweden)

    Anita L. Michel

    2012-06-01

    Full Text Available The African buffalo (Syncerus caffer is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after ‘Big Five’ in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD, Corridor disease (theileriosis, bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population’s survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.

  20. Geochronology of granitoids and gnaisses from the Rio Maria, Mata Geral farm and Itacaiunas river regions, southern Para, Brazil

    International Nuclear Information System (INIS)

    Montalvao, R.M.G. de; Tassinari, C.C.G.; Bezerra, P.E.L.; Prado, P.

    1984-01-01

    Granitoids and gneisses occurring at Rio Maria, Mata Geral farm and Itacaiunas river regions, southern Para, underwent radiometric age determinations by Rb/Sr method using conventional isochrons. Results obtained from the Rio Maria and Mata Geral farm regions allowed te establishment of a reference 2,600 my Rb/Sr isochron with an initial Sr 87 /Sr 86 ratio of 0.7009. This result resembles the one obtained for granitoids and gneisses hosting rocks of the Serra do Inaja greenstone belt, located some what south of this area, which yielded, in Rb/Sr isochron, a radiometric age of 2,696 + - 79 my with an initial Sr 87 /Sr 86 ratio of 0.701. Results obtained from the Itacaiunas river region allowed for the establishment of a Rb/Sr referential isochron of 2,480 + - 40 my wth an initial Sr 87 /.Sr 86 ratio of 0.7072. Due to low initial ratios, it is suggested that the rocks from the Rio Maria, Mata Geral farm and Serra do Inaja regions formed from Mafic crust or superior mantle reworking, while those from the Itacaiunas river region, due to a high initial ratio, result from reworking at high crustal levels. (Author) [pt

  1. The influence of El Niño-Southern Oscillation regimes on eastern African vegetation and its future implications under the RCP8.5 warming scenario

    Science.gov (United States)

    Fer, Istem; Tietjen, Britta; Jeltsch, Florian; Wolff, Christian

    2017-09-01

    The El Niño-Southern Oscillation (ENSO) is the main driver of the interannual variability in eastern African rainfall, with a significant impact on vegetation and agriculture and dire consequences for food and social security. In this study, we identify and quantify the ENSO contribution to the eastern African rainfall variability to forecast future eastern African vegetation response to rainfall variability related to a predicted intensified ENSO. To differentiate the vegetation variability due to ENSO, we removed the ENSO signal from the climate data using empirical orthogonal teleconnection (EOT) analysis. Then, we simulated the ecosystem carbon and water fluxes under the historical climate without components related to ENSO teleconnections. We found ENSO-driven patterns in vegetation response and confirmed that EOT analysis can successfully produce coupled tropical Pacific sea surface temperature-eastern African rainfall teleconnection from observed datasets. We further simulated eastern African vegetation response under future climate change as it is projected by climate models and under future climate change combined with a predicted increased ENSO intensity. Our EOT analysis highlights that climate simulations are still not good at capturing rainfall variability due to ENSO, and as we show here the future vegetation would be different from what is simulated under these climate model outputs lacking accurate ENSO contribution. We simulated considerable differences in eastern African vegetation growth under the influence of an intensified ENSO regime which will bring further environmental stress to a region with a reduced capacity to adapt effects of global climate change and food security.

  2. Ethno-botanical study of the African star apple (Chrysophyllum albidum G. Don in the Southern Benin (West Africa

    Directory of Open Access Journals (Sweden)

    Houessou Laurent G

    2012-10-01

    Full Text Available Abstract Background In addition to plant species biology and ecology, understanding the folk knowledge systems related to the use of plant species and how this knowledge system influences the conservation of plant species is an important issue in the implementation of sustainable strategies of biodiversity conservation programs. This study aimed at providing information on the use and local knowledge variation on Chrysophyllum albidum G. Don a multipurpose tree species widely used in southern Benin. Methods Data was collected through 210 structured interviews. Informants were randomly selected from ten villages. The fidelity level and use value of different plant parts of C. albidum were estimated. The variation in ethnobotanical knowledge was assessed by comparing the use value between ethnic, gender and age groups. In order to assess the use pattern of the different plant parts in folk medicine, a correspondence analysis was carried out on the frequency citation of plant parts. Results Four categories of use (food, medicine, firewood and timber were recorded for C. albidum. With respect to the different plant parts, the fleshy pulp of the African star apple fruit showed high consensus degree as food among the informants. Fifteen diseases were reported to be treated by the different parts of C. albidum in the region. Correspondence analysis revealed the specificity of each part in disease treatment. There was no significant difference among ethnic groups regarding the ethno-botanical use value of C. albidum. However, significant difference existed between genders and among age groups regarding the knowledge of the medical properties of this species. Conclusions C. albidum is well integrated in the traditional agroforestry system of the southern Benin. Despite its multipurpose character, this species remains underutilized in the region. Considering the current threat of habitat degradation, action is needed in order to ensure the long term

  3. Game auction prices are not related to biodiversity contributions of southern African ungulates and large carnivores

    Science.gov (United States)

    Dalerum, Fredrik; Miranda, Maria

    2016-02-01

    There is an urgent need for human societies to become environmentally sustainable. Because public policy is largely driven by economic processes, quantifications of the relationship between market prices and environmental values can provide important information for developing strategies towards sustainability. Wildlife in southern Africa is often privately owned and traded at game auctions to be utilized for commercial purposes mostly related to tourism. This market offers an interesting opportunity to evaluate how market prices relate to biologically meaningful species characteristics. In this market, prices were not correlated with species contributions to either phylogenetic or functional diversity, and species contributions to phylogenetic or functional diversity did not influence the trends in prices over time for the past 20 years. Since this economic market did not seem to appreciate evolutionary or ecologically relevant characteristics, we question if the game tourism market may contribute towards biodiversity conservation in southern Africa. We suggest that market prices in general may have limited values as guides for directing conservation and environmental management. We further suggest that there is a need to evaluate what humans value in biological organisms, and how potentially necessary shifts in such values can be instigated.

  4. Meteorology of the Southern Global Plume: African and South American Fires Pollute the South Pacific

    Science.gov (United States)

    Guo, Z.; Chatfield, R. B.

    1999-01-01

    An immense global plume of CO meanders widely around the world in the Southern Hemisphere. It arises over Southern America and Africa and flows eastward. The first emissions are in tropical Brazil, and the plume circulates around the world to South America again. The plume was largely unexpected until there were aircraft studies made in NASA's Pacific Exploratory Mission - Tropics (Part A). This paper describes the meteorology of the Global Plume, as our simulation, with a synoptic model adapted to global transport, reveals it with a tracer-CO simulation. The observations and their simulation require a particular set of conditions of pollutant accumulation, cumulonimbus venting with required strengths at a narrow range of altitude. Additionally, a particular subtropical conduction region, over the Indian Ocean, Australia, and the westeRNmost South Pacific, relatively free of storms, appears to be a key part of the mechanism. These conclusions are the results of a synoptic reconstruction of the PEMT-A period, September- October, 1996.

  5. Oleistocene mammals in the late-early Holocene in Santa Lucia river basin (Uruguay southern)

    International Nuclear Information System (INIS)

    Ubilla, M.; Perea, D.; Corona, A.; Rinderknecht, A.; Sanchez, A.

    2012-01-01

    This work is about the fossileferous outcrops belongs to the late Pleistocene - early Holocene in Santa Lucia River. It enable to analyse the last records of megafauna vertebrate extinctions (olistecene mammals) with the climate conditions / environment

  6. Ethical quandaries in spiritual healing and herbal medicine: A critical analysis of the morality of traditional medicine advertising in southern African urban societies

    OpenAIRE

    Mawere Munyaradzi

    2011-01-01

    This paper critically examines the morality of advertising by practitioners in spiritual healing and herbal medicine heretofore referred to as traditional medicine, in southern African urban societies. While the subject of traditional medicine has been heavily contested in medical studies in the last few decades, the monumental studies on the subject have emphasised the place of traditional medicine in basic health services. Insignificant attention has been devoted to examine the ethical prob...

  7. Impact of river basin management on coastal water quality and ecosystem services: A southern Baltic estuary

    Science.gov (United States)

    Schernewski, Gerald; Hürdler, Jens; Neumann, Thomas; Stybel, Nardine; Venohr, Markus

    2010-05-01

    Eutrophication management is still a major challenge in the Baltic Sea region. Estuaries or coastal waters linked to large rivers cannot be managed independently. Nutrient loads into these coastal ecosystems depend on processes, utilisation, structure and management in the river basin. In practise this means that we need a large scale approach and integrated models and tools to analyse, assess and evaluate the effects of nutrient loads on coastal water quality as well as the efficiency of river basin management measures on surface waters and especially lagoons and estuaries. The Odra river basin, the Szczecin Lagoon and its coastal waters cover an area of about 150,000 km² and are an eutrophication hot-spot in the Baltic region. To be able to carry out large scale, spatially integrative analyses, we linked the river basin nutrient flux model MONERIS to the coastal 3D-hydrodynamic and ecosystem model ERGOM. Objectives were a) to analyse the eutrophication history in the river basin and the resulting functional changes in the coastal waters between early 1960's and today and b) to analyse the effects of an optimal nitrogen and phosphorus management scenario in the Oder/Odra river basin on coastal water quality. The models show that an optimal river basin management with reduced nutrient loads (e.g. N-load reduction of 35 %) would have positive effects on coastal water quality and algae biomass. The availability of nutrients, N/P ratios and processes like denitrification and nitrogen-fixation would show spatial and temporal changes. It would have positive consequences for ecosystems functions, like the nutrient retention capacity, as well. However, this optimal scenario is by far not sufficient to ensure a good coastal water quality according to the European Water Framework Directive. A "good" water quality in the river will not be sufficient to ensure a "good" water quality in the coastal waters. Further, nitrogen load reductions bear the risk of increased

  8. Water quality assessment of the Shatt al-Arab River, Southern Iraq

    Directory of Open Access Journals (Sweden)

    Mohammad Salim Moyel

    2015-06-01

    Full Text Available Objective: To assess suitability of the water quality of Shatt al-Arab River for protection of aquatic life, potable water supply and irrigation uses. Methods: The Shatt al-Arab River was monitored on a monthly basis from July 2009 to June 2010. A water quality index (WQI was calculated to assess the suitability of water for protection of aquatic life, potable water supply and irrigation uses during the dry season from July to December 2009 and the wet season from January until June 2010. Results: The results of the WQI showed that the lowest water quality values were scored during the dry season for all three uses of the river. Marginal water quality values were recorded for protection of aquatic life and fair (upstream to poor (downstream water quality values were recorded for irrigation uses. Moreover, the river water was not suitable for potable water supply without elaborate treatment. Conclusions: Deterioration of the Shatt al-Arab water quality has been attributed to reduced freshwater discharges from Tigris and Euphrates Rivers, low annual precipitations and an advancing salt wedge from the Arabian Gulf. However, a combination of those factors such as low riverine discharge and advancing salt wedge with a continuous discharge of agriculture, oil industry and urban point effluent has polluted the waters and fostered the decline of the Shatt al-Arab River water quality during the study period. The study indicated that application of WQIs was a useful tool to monitor and assess the overall water quality of the Shatt al-Arab River.

  9. Measuring conditions and trends in ecosystem services at multiple scales: the Southern African Millennium Ecosystem Assessment (SAfMA) experience.

    Science.gov (United States)

    van Jaarsveld, A S; Biggs, R; Scholes, R J; Bohensky, E; Reyers, B; Lynam, T; Musvoto, C; Fabricius, C

    2005-02-28

    The Southern African Millennium Ecosystem Assessment (SAfMA) evaluated the relationships between ecosystem services and human well-being at multiple scales, ranging from local through to sub-continental. Trends in ecosystem services (fresh water, food, fuel-wood, cultural and biodiversity) over the period 1990-2000 were mixed across scales. Freshwater resources appear strained across the continent with large numbers of people not securing adequate supplies, especially of good quality water. This translates to high infant mortality patterns across the region. In some areas, the use of water resources for irrigated agriculture and urban-industrial expansion is taking place at considerable cost to the quality and quantity of freshwater available to ecosystems and for domestic use. Staple cereal production across the region has increased but was outstripped by population growth while protein malnutrition is on the rise. The much-anticipated wood-fuel crisis on the subcontinent has not materialized but some areas are experiencing shortages while numerous others remain vulnerable. Cultural benefits of biodiversity are considerable, though hard to quantify or track over time. Biodiversity resources remain at reasonable levels, but are declining faster than reflected in species extinction rates and appear highly sensitive to land-use decisions. The SAfMA sub-global assessment provided an opportunity to experiment with innovative ways to assess ecosystem services including the use of supply-demand surfaces, service sources and sink areas, priority areas for service provision, service 'hotspots' and trade-off assessments.

  10. Uniting Christian Students� Association�s pilgrimage to overcome colonial racism: A southern African postcolonial missiological dialogue

    Directory of Open Access Journals (Sweden)

    R.W. (Reggie Nel

    2015-03-01

    Full Text Available World Christianity has been enriched by Christian student movements such as the Uniting Christian Students� Association (UCSA from South Africa. This article, based on my recent doctoral research, starts with the affirmation of the ambiguous relations of these movements with colonial racism. However, faced with new challenges in a postcolonial context, there are key impulses to be gained by an inter-subjective, but also interdisciplinary dialogue with these movements as they negotiate their calling. By focussing on one movement within the southern African context, UCSA, in particular its formation and development since the demise of apartheid in South Africa, the article aims to present an attempt to understand the missionary praxis of UCSA through a postcolonial missiological matrix. The article draws on the theological disciplines of missiology, systematic theology, church history, contextual theology, as well as the methodologies in non-theologic disciplines like sociology, in particular social movement studies, and history. The findings show, amongst others, a growing complexity in relation to its agency, how it frames its world and also how it used its authoritative sources to discern its calling. The article closes with some key insights and pointers relevant for faith communities in their mission to overcome colonial racism.Intradisciplinary and/or interdisciplinary implications: The teaching and research in missiology and systematic theology in how the challenge of colonial racism is addressed, methodologically.

  11. Focus on CSIR research in pollution waste: The South African river health programme

    CSIR Research Space (South Africa)

    Hill, Liesl

    2007-08-01

    Full Text Available the design of the River Health Programme (RHP) to monitor the health of rivers in South Africa. The RHP forms part of a bigger initiative, the National Aquatic Ecosystem Health Monitoring Programme which will eventually cover all surface water resources...

  12. Spatial distribution of organic contaminants in three rivers of Southern England bound to suspended particulate material and dissolved in water.

    Science.gov (United States)

    Wilkinson, John L; Hooda, Peter S; Swinden, Julian; Barker, James; Barton, Stephen

    2017-09-01

    The spatial distribution of pharmaceuticals, personal care products (PPCPs) and other emerging contaminants (ECs) such as plasticisers, perflourinated compounds (PFCs) and illicit drug metabolites in water and bound to suspended particulate material (SPM) is not well-understood. Here, we quantify levels of thirteen selected contaminants in water (n=88) and their partition to suspended particulate material (SPM, n=16) in three previously-unstudied rivers of Greater London and Southern England during a key reproduction/spawning period. Analysis was conducted using an in-house validated method for Solid Phase Extraction followed by High-Performance Liquid Chromatography-Tandem Mass-Spectrometry. Analytes were extracted from SPM using an optimised method for ultrasonic-assisted solvent extraction. Detection frequencies of contaminants dissolved in water ranged from 3% (ethinylestradiol) to 100% (bisphenol-A). Overall mean concentrations in the aqueous-phase ranged from 14.7ng/L (benzoylecgonine) to 159ng/L (bisphenol-A). Sewage treatment works (STW) effluent was the predominant source of pharmaceuticals, while plasticisers/perfluorinated compounds may additionally enter rivers via other sources. In SPM, detection frequencies ranged from 44% (PFOA) to 94% (hydroxyacetophenone). Mean quantifiable levels of analytes bound to SPM ranged from 13.5ng/g dry SPM (0.33ng bound/L water) perfluorononanoic acid to 2830ng/g dry SPM (14.3ng bound/L water) perfluorooctanesulfonic acid. Long chain (>C7) amphipathic and acidic PFCs were found to more preferentially bind to SPM than short chain PFCs and other contaminants (Kd=34.1-75.5 vs contaminants entering rivers ranged from 0.157μg/person/day of benzoylecgonine (cocaine metabolite) to 58.6μg/person/day of bisphenol-A. The large sample size of this work (n=104) enabled ANOVA followed by Tukey HSD post-hoc tests to establish significant trends in PPCP/EC spatial distribution from headwaters through downstream stretches of studied

  13. Establishing the environmental flow regime for the Middle Zambezi River

    NARCIS (Netherlands)

    Mwelwa-Mutekenya-Mwelwa, E.

    2016-01-01

    The Middle Zambezi, host to a rich biodiversity, is located in the central part of the Zambezi River Basin which covers eight Southern African Countries. The area is located downstream of three hydropower schemes. In the last decades, the floodplain riparian tree, the Faidherbia albida, vital for

  14. Establishing the Environmental Flow Regime for the Middle Zambezi River

    NARCIS (Netherlands)

    Mwelwa-Mutekenya, E.

    2016-01-01

    The Middle Zambezi, host to a rich biodiversity, is located in the central part of the Zambezi River Basin which covers eight Southern African Countries. The area is located downstream of three hydropower schemes. In the last decades, the floodplain riparian tree, the Faidherbia albida, vital for

  15. Do national drug policies influence antiretroviral drug prices? Evidence from the Southern African Development community.

    Science.gov (United States)

    Liu, Yao; Galárraga, Omar

    2017-03-01

    The efficacy of low- and middle-income countries’ (LMIC) national drug policies in managing antiretroviral (ARV) pharmaceutical prices is not well understood. Though ARV drug prices have been declining in LMIC over the past decade, little research has been done on the role of their national drug policies. This study aims to (i) analyse global ARV prices from 2004 to 2013 and (ii) examine the relationship of national drug policies to ARV prices. Analysis of ARV drug prices utilized data from the Global Price Reporting Mechanism from the World Health Organization (WHO). Ten of the most common ARV drugs (first-line and second-line) were selected. National drug policies were also assessed for 12 countries in the South African Development Community (SADC), which self-reported their policies through WHO surveys. The best predictor of ARV drug price was generic status—the generic versions of 8 out of 10 ARV drugs were priced lower than branded versions. However, other factors such as transaction volume, HIV prevalence, national drug policies and PEPFAR/CHAI involvement were either not associated with ARV drug price or were not consistent predictors of price across different ARV drugs. In the context of emerging international trade agreements, which aim to strengthen patent protections internationally and potentially delay the sale of generic drugs in LMIC, this study shines a spotlight on the importance of generic drugs in controlling ARV prices. Further research is needed to understand the impact of national drug policies on ARV prices.

  16. Molecular characterization of Giardia duodenalis cysts in the Oreto River (Sicily, Southern Italy

    Directory of Open Access Journals (Sweden)

    Maria Antonella Di Benedetto

    2010-03-01

    Full Text Available

    Background: The presence of Giardia was investigated along the Oreto river between January 2008 and May 2009 with the aim of understanding the source of contamination by molecular typing of cysts.

    Methods: A total of 38 water samples (10 collected from the river mouth, 24 from the whole Oreto basin and 4 sewage samples from the Monreale treatment plant were processed. In addition, 22 faecal samples of livestock living close to the Oreto area, were analyzed. The presence of Giardia was determined by immunofluorescence assay and their genetic characterization was achieved by a nested PCR assay targeting the triosephosphate isomerase gene.

    Results: All water samples from the river mouth were positive for Giardia, even if the concentration of cysts fluctuated considerably among sampling occasions. Our investigation showed that the Vadduneddu and Altofonte torrents, two influents of the river, were the principal sources of contamination. Moreover, the genotypes of Vadduneddu torrent were the same as those detected in human wastewater taken from the activated sludge plant of Monreale city. Assemblages A and B were found in water samples with a predominance of Assemblage A, subtype AII. Assemblage E was only found in a single calf isolate.

    Conclusions: The data show that the high cyst counts regularly detected in the Oreto river are due to contamination with wastewater of human origin. This finding is relevant for public health, particularly because river water is used for agricultural purposes.

  17. Hydrological modeling of the semi-arid Andarax river basin in Southern Spain

    DEFF Research Database (Denmark)

    Andersen, Flemming Hauge; Jensen, Karsten Høgh; Sandholt, Inge

    as this it will lead to better estimate of the groundwater recharge and hereby of the groundwater availability in the delta region.   The hydrological behaviour of the Andarax river basin is simulated by the MIKE SHE code, which is a physically based, distributed and integrated hydrological model. In the first...... scenario we only use traditional meteorological data and standard values for the vegetation characteristics. The traditional meteorological data are rather sparse for the Andarax river basin and to improve the estimation of evapotranspiration we use an energy-based two-layer SVAT model and apply remote...

  18. Transgressing the norm: Transformative agency in community-based learning for sustainability in southern African contexts

    Science.gov (United States)

    Lotz-Sisitka, Heila; Mukute, Mutizwa; Chikunda, Charles; Baloi, Aristides; Pesanayi, Tichaona

    2017-12-01

    Environment and sustainability education processes are often oriented to change and transformation, and frequently involve the emergence of new forms of human activity. However, not much is known about how such change emerges from the learning process, or how it contributes to the development of transformative agency in community contexts. The authors of this article present four cross-case perspectives of expansive learning and transformative agency development in community-based education in southern Africa, studying communities pursuing new activities that are more socially just and sustainable. The four cases of community learning and transformative agency focus on the following activities: (1) sustainable agriculture in Lesotho; (2) seed saving and rainwater harvesting in Zimbabwe; (3) community-based irrigation scheme management in Mozambique; and (4) biodiversity conservation co-management in South Africa. The case studies all draw on cultural-historical activity theory to guide learning and change processes, especially third-generation cultural-historical activity theory (CHAT), which emphasises expansive learning in collectives across interacting activity systems. CHAT researchers, such as the authors of this article, argue that expansive learning can lead to the emergence of transformative agency. The authors extend their transformative agency analysis to probe if and how expansive learning might also facilitate instances of transgressing norms - viewed here as embedded practices which need to be reframed and changed in order for sustainability to emerge.

  19. Assessment of radiation background level of Shandong basin in east line of northward rerouting of southern river

    International Nuclear Information System (INIS)

    Deng Daping; Xu Jiaang; Zhu Jianguo; Chen Yingmin; Lu Feng; Song Gang; Cao Jingli

    2007-01-01

    Objective: To assess the radiation background levels of Shandong basin in east line of northward rerouting of southern river. Methods: The activity concentrations of gross-alpha, gross-beta, 137 Cs, 238 U, 232 Th, 40 K, 226 Ra and 90 Sr in the samples were measured by national standard methods respectively. The values of the dose conversion factor given by UNSCEAR 2000 were adopted for dose estimation. Results: The average activity concentrations of gross-alpha, gross-beta, 137 Cs, 238 U, 232 Th, 40 K, 226 Ra and 90 Sr in the samples were pooled in order to analyze dose estimation. The committed effective doses of the 226 Ra, 238 U, 90 Sr, 232 Th and 137 Cs from lake water for residents are 1.46, 4.95 x 10 -1 , 1.24 x 10 -1 , 2.58 x 10 -2 and 7.93 x 10 -3 μSv per year respectively. The committed effective doses of the 226 Ra, 238 U and 90 Sr from cyprinoid fish are 5.49 x 10 -2 , 3.69 x 10 -2 and 1.77 x 10 -2 μSv per year respectively. Conclusions: The results show that the average activity concentrations of gross-alpha, gross-beta, 137 Cs, 238 U, 232 Th, 40 K, 226 Ra and 90 Sr in the samples from Shandong basin of northward rerouting of southern river are within the background levels. And in the main lake basin, the estimated exposures of public caused by the radionuclide in water and cyprinoid fish are so low that they can be ignored unless there ate some radioactive contamination in the future. (authors)

  20. The influence of Pleistocene climatic changes and ocean currents on the phylogeography of the southern African barnacle, Tetraclita serrata (Thoracica; Cirripedia.

    Directory of Open Access Journals (Sweden)

    Terry V Reynolds

    Full Text Available The evolutionary effects of glacial periods are poorly understood for Southern Hemisphere marine intertidal species, particularly obligatory sessile organisms. We examined this by assessing the phylogeographic patterns of the southern African volcano barnacle, Tetraclita serrata, a dominant species on rocky intertidal shores. Restricted gene flow in some geographical areas was hypothesized based on oceanic circulation patterns and known biogeographic regions. Barnacle population genetic structure was investigated using the mitochondrial cytochrome oxidase subunit 1 (COI region for 410 individuals sampled from 20 localities spanning the South African coast. The mtDNA data were augmented by generating nuclear internal transcribed spacer 1 (ITS1 sequences from a subset of samples. Phylogenetic and population genetic analyses of mitochondrial DNA data reveal two distinct clades with mostly sympatric distributions, whereas nuclear analyses reveal only a single lineage. Shallow, but significant structure (0.0041-0.0065, P<0.01 was detected for the mtDNA data set, with the south-west African region identified as harbouring the highest levels of genetic diversity. Gene flow analyses on the mtDNA data show that individuals sampled in south-western localities experience gene flow primarily in the direction of the Benguela Current, while south and eastern localities experience bi-directional gene flow, suggesting an influence of both the inshore currents and the offshore Agulhas Current in the larval distribution of T. serrata. The mtDNA haplotype network, Bayesian Skyline Plots, mismatch distributions and time since expansion indicate that T. serrata population numbers were not severely affected by the Last Glacial Maximum (LGM, unlike other southern African marine species. The processes resulting in the two morphologically cryptic mtDNA lineages may be the result of a recent historical allopatric event followed by secondary contact or could reflect

  1. Infant mortality among offspring of individuals living in the radioactively contaminated Techa River Area, Southern Urals

    International Nuclear Information System (INIS)

    Ostroumova, E.; Akleyev, A.; Hall, P.

    2005-01-01

    Massive discharge of liquid radioactive wastes into the Techa River in 1949-1956 by the industrial complex Mayak for production of plutonium for weapon resulted in protracted internal and external radiation exposure of the population living along the river. The Techa River Offspring Cohort comprises individuals born after December 31, 1949, whose one or both parents were exposed in the Techa riverside villages. The study group includes 7,897 individuals. About 40% of the Techa River Offspring Cohort members born in 1950-1956 could be exposed in utero and after birth. The mean dose estimates based on the Techa River Dosimetry System 2000 were: 0.07 Gy for parental gonads, 0.01 Gy for fetus and 0.02 Gy for postnatal exposure of bone marrow. Over 46 years of follow-up from 1950-1995, 916 subjects died and the cause of death was known in 93% of them. Out of 916 subjects dead, 456 (53%) died under 1 year of age, mainly due to respiratory tract diseases (38% of all infant deaths), infections (27%) and perinatal disorders (13%). It has been shown that the baseline infant mortality rate depends on gender, ethnicity and birth year. Radiation risk analysis was based on a simple parametric linear excess relative risk model with adjustment for gender, ethnicity and birth year. There was no evidence of increasing infant mortality risk with parental gonadal dose. The infant mortality rate significantly depended on fetal dose and dose to bone marrow received during the first year of life with a 3% increase in risk per 1 cGy of intrauterine and postnatal doses. (author)

  2. Spatial Heterogeneity and Sources of Soil Carbon in Southern African Savannas

    Science.gov (United States)

    Macko, S.; Wang, L.; Okin, G.

    2007-12-01

    Soil organic carbon (SOC) is one of the largest and most dynamic reservoirs of C on Earth, with nearly twice as much C stored in SOC than in the biosphere and atmosphere combined. SOC storage in global tropical savannas constitutes approximately 56 Gt of C, which rises to 216 Gt of C (i.e., about 17% of the terrestrial non- agricultural SOC), when woodlands, shrublands, and desert scrub are included. Savannas cover about 20% of the global land surface, including about one-half of Africa, Australia and South America. The shared dominance of trees and grasses in savannas, the dominant physiognomy in southern Africa, add more complexity to soil C pool partitioning and dynamics than is found in landscapes with a single physiognomy. Here, the spatial variability of the soil C pool was investigated with particular emphasis on understanding the contribution to SOC from trees and grasses at two savanna sites of the Kalahari Transect, one wet and the other dry. Using a combination of stable isotope techniques and geostatistics, the results showed that spatial patterns of soil δ13 C exist and were related to the distributions of woody (C3) and herbaceous (C4) vegetation at both sites. Heterogeneity of the sources of SOC, as well as heterogeneity in the amount of SOC, was greater at the dry site relative to the wet site. At the dry site, the grasses were the major contributor to soil C whereas in the wet site, woody vegetation was the major contributor, regardless of the location with respect to woody canopies.

  3. Differential range use between age classes of southern African Bearded Vultures Gypaetus barbatus.

    Directory of Open Access Journals (Sweden)

    Sonja Krüger

    Full Text Available Bearded Vulture Gypaetus barbatus movements were investigated in southern Africa to determine whether an individual's age, sex or breeding status influenced its ranging behaviour and to provide the information required to guide conservation activities. Data from satellite transmitters fitted to 18 individuals of four age classes were used to determine range size and use. Because of the nature of the movements of marked individuals, these data could be used to determine the overall foraging range of the entire population, which was estimated to be 51 767 km(2. Although juvenile, immature and sub-adult birds used different parts of the overall range, their combined foraging range was 65% (33 636 km(2 of the overall range. Average adult home ranges (286 km(2 were only around 1% the size of the average foraging ranges of non-adults (10 540 -25 985 km(2, with those of breeding adults being even smaller (95 km(2. Home ranges of breeding adults did not vary in size between seasons but adults utilized their home range more intensively whilst breeding, moving greater distances during the incubation and chick hatching period. Range size and use increased as non-adults aged. Immatures and sub-adults had larger range sizes during winter, but range use of non-adults did not vary seasonally. Range size and use did not differ between the sexes in any of the age classes. Information on home range size and use enables specific areas within the species' range to be targeted for management planning, education and conservation action.

  4. Use of landscape-level river signatures in conservation planning: a South African case study

    CSIR Research Space (South Africa)

    Roux, D

    2002-12-01

    Full Text Available ecosystems of this area, a desktop approach, supplemented by aerial and land surveys, was used to devise a new river classification typology. This typology incorporated landscape attributes as surrogates for biodiversity patterns, resulting in defined...

  5. Invasive alien plants and South African rivers: a proposed approach to the prioritisation of control operations

    CSIR Research Space (South Africa)

    Van Wilgen, BW

    2007-01-01

    Full Text Available Parallel initiatives in South Africa have been addressing the prioritisation and management of invasive alien plant species, the prioritisation of rivers for the conservation of biodiversity, and broad-scale planning for water resource management...

  6. Species richness and abundance of bats in fragments of the stational semidecidual forest, Upper Paraná River, southern Brazil

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    H. Ortêncio-Filho

    Full Text Available The Upper Paraná River floodplain is inserted in a region of the Mata Atlântica biome, which is a critical area to preserve. Due to the scarcity of researches about the chiropterofauna in this region, the present study investigated species richness and abundance of bats in remnants from the stational semidecidual forest of the Upper Paraná River, southern Brazil. Samplings were taken every month, from January to December 2006, using 32 mist nets with 8.0 x 2.5 m, resulting in 640 m²/h and totaling a capture effort of 87,040 m²/h. In order to estimate the species richness, the following estimators were employed Chao1 and Jack2. During the study, a total of 563 individuals belonging to 17 species (Artibeus planirostris, Artibeus lituratus, Carollia perspicillata, Platyrrhinus lineatus, Sturnira lilium, Artibeus fimbriatus, Myotis nigricans, Desmodus rotundus, Artibeus obscurus, Noctilio albiventris, Phylostomus discolor, Phylostomus hastatus, Chrotopterus auritus, Lasiurus ega, Chiroderma villosum, Pygoderma bilabiatum and Lasiurus blossevillii were captured. The estimated richness curves tended to stabilize, indicating that most of the species were sampled. Captured species represented 10% of the taxa recorded in Brazil and 28% in Paraná State, revealing the importance of this area for the diversity of bats. These findings indicate the need to determine actions aiming to restrict human activities in these forest fragments, in order to minimize anthropogenic impacts on the chiropterofauna.

  7. Decline of General Intelligence in Children Exposed to Manganese from Mining Contamination in Puyango River Basin, Southern Ecuador.

    Science.gov (United States)

    Betancourt, Óscar; Tapia, Marlene; Méndez, Ignacio

    2015-09-01

    Based on ecosystem approaches to health (Ecohealth), this study sought to identify neurobehavioral disorders in children exposed to several levels of toxic metal pollution from gold mining in the Puyango River Basin, Southern Ecuador. Ninety-three children born or living in the study area participated in the study. A neurobehavioral test battery consisting of 12 tests assessing various functions of the nervous system was applied as well as a questionnaire regarding events of exposure of children's mothers to contaminants during perinatal period. Hair samples were taken from children to determine manganese concentrations. Descriptive and inferential statistics were applied in order to examine possible relationships between exposure events, hair manganese, and neurobehavioral disorders. Having controlled co-variables such as age and educational level, it was found that children with elevated levels of hair manganese (over 2 μg/g) had poor performance in the test of general intelligence (Raven's Progressive Color Matrices Scale PCM). The Ecohealth approach helped to identify that children in the lower Puyango Basin with very elevated levels of manganese in the river water (970 µg/L) are the ones who have the highest levels of hair manganese and the worst performance in the intelligence test.

  8. Assessing the spatial pattern of a river water quality in southern Brazil by multivariate analysis of biological and chemical indicators

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    M. B. B. Cassanego

    Full Text Available Abstract This study assessed the genotoxicity and chemical quality of the Rio dos Sinos, southern Brazil. During two years, bimonthly, cuttings of Tradescantia pallida var. purpurea with flower buds were exposed to river water samples from Caraá, Santo Antônio da Patrulha, Taquara and Campo Bom, which are municipalities located in the upper, middle and lower stretches of the Rio dos Sinos basin. Simultaneously, chemical parameters were analyzed, rainfall data were surveyed and negative (distilled water and positive (0.1% formaldehyde controls were made. Micronuclei (MCN frequencies were determined in tetrads of pollen grain mother cells. From the upper stretch toward the lower, there was an increase in the frequency of MCN and in concentrations of chemical parameters. Cadmium, lead, copper, total chromium and zinc were present at the four sites and a concentration gradient was not demonstrated along the river. The multivariate analysis revealed that two principal components exist, which accounted for 62.3% of the observed variances. Although genotoxicity was observed in Santo Antônio da Patrulha, the water presented higher mean values for most of the assessed parameters, in the lower stretch, where urbanization and industrialization are greater. The spatial and temporal pattern of water quality observed reinforces the importance of considering the environmental factors and their effects on organisms in an integrated way in watercourse monitoring programs.

  9. Heavy metal contamination of agricultural soils affected by mining activities around the Ganxi River in Chenzhou, Southern China.

    Science.gov (United States)

    Ma, Li; Sun, Jing; Yang, Zhaoguang; Wang, Lin

    2015-12-01

    Heavy metal contamination attracted a wide spread attention due to their strong toxicity and persistence. The Ganxi River, located in Chenzhou City, Southern China, has been severely polluted by lead/zinc ore mining activities. This work investigated the heavy metal pollution in agricultural soils around the Ganxi River. The total concentrations of heavy metals were determined by inductively coupled plasma-mass spectrometry. The potential risk associated with the heavy metals in soil was assessed by Nemerow comprehensive index and potential ecological risk index. In both methods, the study area was rated as very high risk. Multivariate statistical methods including Pearson's correlation analysis, hierarchical cluster analysis, and principal component analysis were employed to evaluate the relationships between heavy metals, as well as the correlation between heavy metals and pH, to identify the metal sources. Three distinct clusters have been observed by hierarchical cluster analysis. In principal component analysis, a total of two components were extracted to explain over 90% of the total variance, both of which were associated with anthropogenic sources.

  10. Systematics of the hypervariable Moraea tripetala complex (Iridaceae: Iridoideae of the southern African winter rainfall zone

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    P. Goldblatt

    2012-12-01

    Full Text Available Field and laboratory research has shown that the Moraea tripetala complex of western South Africa, traditionally treated as a single species, sometimes with two additional varieties, has a pattern of morphological and cytological variation too complex to be accommodated in a single species. Variation in floral structure, especially the shape of the inner tepals, degree of union of the filaments, anther length and pollen colour form coherent patterns closely correlated with morphology of the corm tunics, mode of vegetative reproduction, and in some instances capsule and seed shape and size. The morphological patterns also correlate with geography, flowering time and sometimes habitat. It is especially significant that different variants of the complex may co-occur, each with overlapping or separate flowering times, a situation that conflicts with a single species taxonomy. We propose recognizing nine species and three additional subspecies for plants currently assigned to M. tripetala. M. grandis, from the western Karoo, has virtually free filaments and leaves often ± plane distally; closely allied M. amabilis, also with ± free filaments and often hairy leaves, is centred in the western Karoo and Olifants River Valley. Its range overlaps that of M. cuspidata, which has narrowly channelled, smooth leaves, linear inner tepals spreading distally and filaments united for up to 1.5 mm. M. decipiens from the Piketberg, M. hainebachiana, a local endemic of coastal limestone fynbos in the Saldanha District, M. ogamana from seasonally wet lowlands, and early flowering M. mutila constitute the remaining species of the complex in the southwestern Western Cape. M. helmei, a local endemic of middle elevations in the Kamiesberg, Namaqualand, has small flowers with short, tricuspidate inner tepals. All but M. amabilis and M. mutila are new species. We divide M. tripetala sensu stricto into three subspecies: widespread subsp. tripetala, subsp. violacea from

  11. Systematics of the southern African genus Ixia (Iridaceae. 2. The filiform-leaved I. capillaris complex

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    P. Goldblatt

    2008-08-01

    Full Text Available Field study and associated examination of herbarium specimens of the filiform-leaved species of section Morphixia o f the South African genus Ixia L. have resulted in an increase in the number of species with this derived leaf type.  Ixia capillaris and  I. pauciflora have until now been the only species with such leaves and they have not been regarded as immediately related in past accounts of the genus. The two foliage leaves, typically less than 2 mm w ide, with a leathery to succulent texture, and lacking a raised central vein or margins, are specialized in the genus. Associated finely fibrous corm tunics, spikes of 1-3 flowers, and when present, short, thread-like lateral branches, usually bearing 1 or 2 flowers, provide supporting evidence that the group is monophyletic.  I. capillaris as interpreted until now. comprises four species, three of them new and described here, and the large-flowered I. pauciflora includes two species, one of these described here. While I. capillaris has a branched stem, radially symmetric flowers with a penanth tube (4—5—7(—8 mm long, tepals 11-15 mm long and thus substantially exceeding the tube, filaments typically exserted 1-2 mm. and anthers (3—4—5 mm long. I. exiliflora has a tube 8-10 mm long and ± as long as the tepals, included filaments, and anthers 3.5—4.0 mm long. The new  I. dieramoides also has included filaments but a perianth tube 13—18(—22 mm long and tepals 11-18 mm long. A third new species. I. reclinata has large flowers with a tube 13-15 mm long, tepals 16-21 mm long, and unilateral, decimate stamens with the filaments exserted 8-10 mm. and anthers 4-5 mm long. Typical  I. pauciflora has flowers with unilateral stamens and filaments exserted 2-6 mm from the flower and anthers prominently displayed, but specimens until now included in that species w ith short, included filaments 3-5 mm long and anthers half included in the tube, are here regarded as I. dieramoides. The I

  12. Diel and seasonal movements of grumatã Prochilodus lineatus (Valenciennes 1836 (Characiformes: Prochilodontidae in the Sinos River, Southern Brazil

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    NA. Pesoa

    Full Text Available Prochilodus lineatus is a reophilic migratory species of economical importance for local fisheries which is widely distributed in Brazil. The present study investigated diel and seasonal movement patterns, spawning migration and habitat use of P. lineatus in the Sinos River, Southern Brazil. Between August 2002 and March 2004, 19 grumatãs were tagged internally with digitally coded radio transmitters. Tracking was conducted weekly by boat or aircraft, and six fixed data loggers recorded movements of tagged fish. Results showed that the mean distance covered per fish and day was positively related with fish weight (p = 0.03; n = 19. Grumatã showed preference for river streches surrounded by wetlands (p < 0.001; n = 286. Their diel activity pattern displayed one peak at 7 hours, and a second at 15 hours. During the night, activity was significantly reduced (p = 0.01. The seasonal movements pattern showed increased activity in October 2002 - March 2003 and from October 2003 to January 2004. Multiple regression analysis did not show a significant relationship between distance covered and temperature or water level (p = 0.116; n = 19. No synchronized long distance spawning migrations were observed. The mean distance covered by the individuals/day showed a negative significant relationship with number of tracking days (p = 0.022; n = 19, indicating a higher probability of being captured for more mobile individuals. The preservation of the still existing wetlands and reduction of the fishing pressure are essential for the future conservation of the grumatã population of the Sinos River.

  13. Romulea pilosa and R. quartzicola (Iridaceae: Crocoideae, two new species from the southern African winter rainfall region, with nomenclatural corrections

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    J. C. Manning

    2011-12-01

    Full Text Available Romulea pilosa J.C.Manning & Goldblatt and R. quartzicola J.C.Manning & Goldblatt are two narrow endemics from the southern African winter rainfall region. An early, fragmentary collection of R. pilosa from Riviersonderend lacked the diagnostic corm and was thus mistakenly associated with R. tetragona (sect. Ciliatae as var. flavandra M.P.de Vos because of the highly distinctive pilose, H-shaped leaf. The rediscovery of the taxon in the wild shows it to be a previously unrecognized member of sect. Aggregatae, distinguished by its unusual foliage and bright orange flowers. R. quartzicola was grown to flowering from seeds collected from quartz patches in southern Namaqualand and proved to be a new species of sect. Ciliatae, distinguished by its early flowering, short, subclavate leaves with reduced sclerenchyma strands, and bright yellow flowers with short bracts. R. neglecta M.P.de Vos, a rare endemic from the Kamiesberg in Northern Cape, is a later homonym for the Mediterranean R. neglecta Jord. & Fourr., and the earliest name for this plant is shown to be R. speciosa (Ker Gawl. Baker, typified by an illustration in Andrews’ The botanist’s repository. An epitype is designated to fix the application of the name. We have also examined the type illustration of R. pudica (Sol. ex Ker Gawl. Baker, hitherto treated as an uncertain species, and are confident that it represents the species currently known as R. amoena Schltr. ex Bég., and takes priority over it as being the earlier name. The type of R. reflexa Eckl., a new name for the later homonym I. reflexa Thunb. and the basionym of R. rosea var. reflexa (Eckl. Bég., has been mistakenly identified as an Ecklon collection but is in fact the collection that formed the basis of Thunberg’s I. reflexa. This collection is actually a form of R. flava Lam., and the name R. rosea var. reflexa is thus moved to the synonomy of that species. The variety currently known under this name should now be

  14. New synonyms and a new name in Asteraceae: Senecioneae from the southern African winter rainfall region

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    J. C. Manning

    2010-07-01

    Full Text Available A review of the genera Othonna and Senecio undertaken for the forthcoming Greater Cape plants 2: Namaqualand-southern Namib and western Karoo (Manning in prep. led to a re-examination of the taxonomic status of several species. This was facilitated by the recent availability of high-resolution digital images on the Aluka website (www.aluka.org of the Drege isotypes in the Paris Herbarium that formed the basis of many species described by De Candolle in his Prodromus systematis naturalis regni vegetabilis. These images made it possible to identify several names whose application had remained uncertain until now. Each case is briefly discussed, with citation of additional relevant herbarium specimens. The following species are reduced to synonomy: O. incisa Harv. is included in O. rosea Harv.; O. spektakelensis Compton and O. zeyheri Sond. ex Harv. are included in O. retrorsa DC.; S. maydae Merxm. is included in S. albopunctatus Bolus, which is now considered to include forms with radiate and discoid capitula; S. cakilefolius DC. is included in  O. arenarius Thunb.; S. pearsonii Hutch, is included in O. aspertdus DC.; S. parvifolius DC. is included in S. carroensis DC.; S. eriobasis DC. is included in S. erosus L.f.; and S. lobelioides DC. is included in S. flavus (Decne. Sch.Bip. The name S. panduratus (Thunb. Less, is identified as a synonym of S. erosus L.f. and plants that are currently know n under this name should be called S. robertiifolius DC. The confusion in the application o f the names O. perfoliata (L.f. Jacq. and O. filicaulis Jacq. is examined. O. perfoliata is lecto- typified against a specimen in the Linnaean Herbarium (LINN  w ith radiate capitula. The name O. filicaulis correctly applies to a radiate species and is treated as a synonym of O. perfoliata. The vegetatively similar taxon with disciform capitula that is currently known as O. filicaulis should be known as (  undulosa (DC. J.C.Manning  & Goldblatt, comb. nov. The

  15. Scrubbing Up: Multi-Scale Investigation of Woody Encroachment in a Southern African Savannah

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    Christopher G. Marston

    2017-04-01

    Full Text Available Changes in the extent of woody vegetation represent a major conservation question in many savannah systems around the globe. To address the problem of the current lack of broad-scale cost-effective tools for land cover monitoring in complex savannah environments, we use a multi-scale approach to quantifying vegetation change in Kruger National Park (KNP, South Africa. We test whether medium spatial resolution satellite data (Landsat, existing back to the 1970s, which have pixel sizes larger than typical vegetation patches, can nevertheless capture the thematic detail required to detect woody encroachment in savannahs. We quantify vegetation change over a 13-year period in KNP, examine the changes that have occurred, assess the drivers of these changes, and compare appropriate remote sensing data sources for monitoring change. We generate land cover maps for three areas of southern KNP using very high resolution (VHR and medium resolution satellite sensor imagery from February 2001 to 2014. Considerable land cover change has occurred, with large increases in shrubs replacing both trees and grassland. Examination of exclosure areas and potential environmental driver data suggests two mechanisms: elephant herbivory removing trees and at least one separate mechanism responsible for conversion of grassland to shrubs, theorised to be increasing atmospheric CO2. Thus, the combination of these mechanisms causes the novel two-directional shrub encroachment that we observe (tree loss and grassland conversion. Multi-scale comparison of classifications indicates that although spatial detail is lost when using medium resolution rather than VHR imagery for land cover classification (e.g., Landsat imagery cannot readily distinguish between tree and shrub classes, while VHR imagery can, the thematic detail contained within both VHR and medium resolution classifications is remarkably congruent. This suggests that medium resolution imagery contains sufficient

  16. Intraspecific venom variation in southern African scorpion species of the genera Parabuthus, Uroplectes and Opistophthalmus (Scorpiones: Buthidae, Scorpionidae).

    Science.gov (United States)

    Schaffrath, Stephan; Prendini, Lorenzo; Predel, Reinhard

    2018-03-15

    Scorpion venoms comprise cocktails of proteins, peptides, and other molecules used for immobilizing prey and deterring predators. The composition and efficacy of scorpion venoms appears to be taxon-specific due to a coevolutionary arms race with prey and predators that adapt at the molecular level. The taxon-specific components of scorpion venoms can be used as barcodes for species identification if the amount of intraspecific variation is low and the analytical method is fast, inexpensive and reliable. The present study assessed the extent of intraspecific variation in newly regenerated venom collected in the field from geographically separated populations of four southern African scorpion species: three buthids, Parabuthus granulatus (Ehrenberg, 1831), Uroplectes otjimbinguensis (Karsch, 1879), and Uroplectes planimanus (Karsch, 1879), and one scorpionid, Opistophthalmus carinatus (Peters, 1861). Although ion signal patterns were generally similar among venom samples of conspecific individuals from different populations, MALDI-TOF mass spectra in the mass range m/z 700-10,000 revealed only a few ion signals that were identical suggesting that species identification based on simple venom mass fingerprints (MFPs) will be more reliable if databases contain data from multiple populations. In general, hierarchical cluster analysis (HCA) of the ion signals in mass spectra was more reliable for species identification than counts of mass-identical substances in MFPs. The statistical approach revealed conclusive information about intraspecific diversity. In combination with a comprehensive database of MALDI-TOF mass spectra in reflectron mode, HCA may offer a method for rapid species identification based on venom MFPs. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Regional trade and the nutrition transition: opportunities to strengthen NCD prevention policy in the Southern African Development Community.

    Science.gov (United States)

    Thow, Anne Marie; Sanders, David; Drury, Eliza; Puoane, Thandi; Chowdhury, Syeda N; Tsolekile, Lungiswa; Negin, Joel

    2015-01-01

    Addressing diet-related non-communicable diseases (NCDs) will require a multisectoral policy approach that includes the food supply and trade, but implementing effective policies has proved challenging. The Southern African Development Community (SADC) has experienced significant trade and economic liberalization over the past decade; at the same time, the nutrition transition has progressed rapidly in the region. This analysis considers the relationship between regional trade liberalization and changes in the food environment associated with poor diets and NCDs, with the aim of identifying feasible and proactive policy responses to support healthy diets. Changes in trade and investment policy for the SADC were documented and compared with time-series graphs of import data for soft drinks and snack foods to assess changes in imports and source country in relation to trade and investment liberalization. Our analysis focuses on regional trade flows. Diets and the burden of disease in the SADC have changed since the 1990s in parallel with trade and investment liberalization. Imports of soft drinks increased by 76% into SADC countries between 1995 and 2010, and processed snack foods by 83%. South Africa acts as a regional trade and investment hub; it is the major source of imports and investment related to these products into other SADC countries. At the same time, imports of processed foods and soft drinks from outside the region - largely from Asia and the Middle East - are increasing at a dramatic rate with soft drink imports growing by almost 1,200% and processed snack foods by 750%. There is significant intra-regional trade in products associated with the nutrition transition; however, growing extra-regional trade means that countries face new pressures in implementing strong policies to prevent the increasing burden of diet-related NCDs. Implementation of a regional nutrition policy framework could complement the SADC's ongoing commitment to regional trade policy.

  18. Regional trade and the nutrition transition: opportunities to strengthen NCD prevention policy in the Southern African Development Community

    Science.gov (United States)

    Thow, Anne Marie; Sanders, David; Drury, Eliza; Puoane, Thandi; Chowdhury, Syeda N.; Tsolekile, Lungiswa; Negin, Joel

    2015-01-01

    Background Addressing diet-related non-communicable diseases (NCDs) will require a multisectoral policy approach that includes the food supply and trade, but implementing effective policies has proved challenging. The Southern African Development Community (SADC) has experienced significant trade and economic liberalization over the past decade; at the same time, the nutrition transition has progressed rapidly in the region. This analysis considers the relationship between regional trade liberalization and changes in the food environment associated with poor diets and NCDs, with the aim of identifying feasible and proactive policy responses to support healthy diets. Design Changes in trade and investment policy for the SADC were documented and compared with time-series graphs of import data for soft drinks and snack foods to assess changes in imports and source country in relation to trade and investment liberalization. Our analysis focuses on regional trade flows. Results Diets and the burden of disease in the SADC have changed since the 1990s in parallel with trade and investment liberalization. Imports of soft drinks increased by 76% into SADC countries between 1995 and 2010, and processed snack foods by 83%. South Africa acts as a regional trade and investment hub; it is the major source of imports and investment related to these products into other SADC countries. At the same time, imports of processed foods and soft drinks from outside the region – largely from Asia and the Middle East – are increasing at a dramatic rate with soft drink imports growing by almost 1,200% and processed snack foods by 750%. Conclusions There is significant intra-regional trade in products associated with the nutrition transition; however, growing extra-regional trade means that countries face new pressures in implementing strong policies to prevent the increasing burden of diet-related NCDs. Implementation of a regional nutrition policy framework could complement the SADC

  19. Regional trade and the nutrition transition: opportunities to strengthen NCD prevention policy in the Southern African Development Community

    Directory of Open Access Journals (Sweden)

    Anne Marie Thow

    2015-07-01

    Full Text Available Background: Addressing diet-related non-communicable diseases (NCDs will require a multisectoral policy approach that includes the food supply and trade, but implementing effective policies has proved challenging. The Southern African Development Community (SADC has experienced significant trade and economic liberalization over the past decade; at the same time, the nutrition transition has progressed rapidly in the region. This analysis considers the relationship between regional trade liberalization and changes in the food environment associated with poor diets and NCDs, with the aim of identifying feasible and proactive policy responses to support healthy diets. Design: Changes in trade and investment policy for the SADC were documented and compared with time-series graphs of import data for soft drinks and snack foods to assess changes in imports and source country in relation to trade and investment liberalization. Our analysis focuses on regional trade flows. Results: Diets and the burden of disease in the SADC have changed since the 1990s in parallel with trade and investment liberalization. Imports of soft drinks increased by 76% into SADC countries between 1995 and 2010, and processed snack foods by 83%. South Africa acts as a regional trade and investment hub; it is the major source of imports and investment related to these products into other SADC countries. At the same time, imports of processed foods and soft drinks from outside the region – largely from Asia and the Middle East – are increasing at a dramatic rate with soft drink imports growing by almost 1,200% and processed snack foods by 750%. Conclusions: There is significant intra-regional trade in products associated with the nutrition transition; however, growing extra-regional trade means that countries face new pressures in implementing strong policies to prevent the increasing burden of diet-related NCDs. Implementation of a regional nutrition policy framework could

  20. Three-dimensional technology for linear morphological studies: a re-examination of cranial variation in four southern African indigenous populations.

    Science.gov (United States)

    Franklin, D; Freedman, L; Milne, N

    2005-01-01

    In order to compare linear dimensions made by traditional anthropometric techniques, and those obtained from three-dimensional coordinates, samples of four indigenous southern African populations were analysed. Linear measurements were obtained using mathematically transformed, three-dimensional landmark data on 207 male crania of Cape Nguni, Natal Nguni, Sotho and Shangaan. Univariate comparisons for accuracy of the transformed linear data were made with those in a traditional linear study by de Villiers (The Skull of the South African Negro: A Biometrical and Morphological Study. Witwatersrand University Press, Johannesburg) on similar samples and equivalent landmarks. Comparisons were not made with her Penrose (Ann Eugenics 18 (1954) 337) analysis as an apparently anomalous 'shape'-'size' statistic was found. The univariate comparisons demonstrated that accurate linear measurements could be derived from three-dimensional data, showing that it is possible to simultaneously obtain data for three-dimensional geometric 'shape' and linear interlandmark analyses. Using Penrose and canonical variates analyses of the transformed three-dimensional interlandmark measurements, similar population distances were found for the four indigenous southern African populations. The inter-population distance relationships took the form of three separated pairs of distances, with the within-pair distances very similar in size. The cranial features of the four populations were found to be overall very similar morphometrically. However the populations were each shown by CVA to have population specific features, and using discriminant analyses 50% or more of the individual crania (with the exception of the Sotho) could be referred to their correct populations.

  1. Full Genome Sequencing Reveals New Southern African Territories Genotypes Bringing Us Closer to Understanding True Variability of Foot-and-Mouth Disease Virus in Africa

    Science.gov (United States)

    Lasecka-Dykes, Lidia; Wright, Caroline F.; Di Nardo, Antonello; Logan, Grace; Mioulet, Valerie; Jackson, Terry; Tuthill, Tobias J.; Knowles, Nick J.; King, Donald P.

    2018-01-01

    Foot-and-mouth disease virus (FMDV) causes a highly contagious disease of cloven-hooved animals that poses a constant burden on farmers in endemic regions and threatens the livestock industries in disease-free countries. Despite the increased number of publicly available whole genome sequences, FMDV data are biased by the opportunistic nature of sampling. Since whole genomic sequences of Southern African Territories (SAT) are particularly underrepresented, this study sequenced 34 isolates from eastern and southern Africa. Phylogenetic analyses revealed two novel genotypes (that comprised 8/34 of these SAT isolates) which contained unusual 5′ untranslated and non-structural encoding regions. While recombination has occurred between these sequences, phylogeny violation analyses indicated that the high degree of sequence diversity for the novel SAT genotypes has not solely arisen from recombination events. Based on estimates of the timing of ancestral divergence, these data are interpreted as being representative of un-sampled FMDV isolates that have been subjected to geographical isolation within Africa by the effects of the Great African Rinderpest Pandemic (1887–1897), which caused a mass die-out of FMDV-susceptible hosts. These findings demonstrate that further sequencing of African FMDV isolates is likely to reveal more unusual genotypes and will allow for better understanding of natural variability and evolution of FMDV. PMID:29652800

  2. Late quaternary dynamics in the Madeira river basin, southern Amazonia (Brazil, as revealed by paleomorphological analysis

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    Ericson H. Hayakawa

    2015-03-01

    Full Text Available Ancient drainage systems are being increasingly documented in the Amazon basin and their characterization is crucial for reconstructing fluvial evolution in this area. Fluvial morphologies, including elongate belts, are well preserved along the Madeira River. Digital Elevation Model from the Shuttle Radar Topography Mission favored the detection of these features even where they are covered by dense rainforest. These paleomorphologies are attributed to the shifting position of past tributaries of the Madeira River through avulsions. These radial paleodrainage networks produced fan-shaped morphologies that resemble distributary megafans. Distinguishing avulsive tributary systems from distributary megafans in the sedimentary record is challenging. Madeira´s paleodrainage reveals the superposition of tributary channels formed by multiple avulsions within a given time period, rather than downstream bifurcation of coexisting channels. Channel avulsion in this Amazonian area during the late Quaternary is related to tectonics due to features as: (i straight lineaments coincident with fault directions; (ii northeastward tilting of the terrain with Quaternary strata; and (iii several drainage anomalies, including frequent orthogonal drainage inflections. These characteristics altogether lead to propose that the radial paleodrainage present at the Madeira River margin results from successive avulsions of tributary channels over time due to tectonics.

  3. Aquatic gilled mushrooms: Psathyrella fruiting in the Rogue River in southern Oregon.

    Science.gov (United States)

    Frank, Jonathan L; Coffan, Robert A; Southworth, Darlene

    2010-01-01

    A species of Psathyrella (Basidiomycota) with true gills has been observed fruiting underwater in the clear, cold, flowing waters of the upper Rogue River in Oregon. Fruiting bodies develop and mature in the main channel, where they are constantly submerged, and were observed fruiting over 11 wk. These mushrooms develop underwater, not on wood recently washed into the river. Substrates include water-logged wood, gravel and the silty riverbed. DNA sequences of the ITS region and a portion of the ribosomal large subunit gene place this fungus in Psathyrella sensu stricto near P. atomata, P. fontinalis and P. superiorensis. Morphological characters distinguish the underwater mushroom from previously described species. Fruiting bodies have long fibrillose stipes with small diameter caps. Immature stages have a thin veil that is soon lost. Gills lack reddish edges. Cystidia are ventricose with subacute apices. Spores were observed as wedge-shape rafts released into gas pockets below the caps. Underwater gills and ballistospores indicate a recent adaptation to the stream environment. This particular river habitat combines the characteristics of spring-fed flows and cold, aerated water with woody debris in shallow depths on a fine volcanic substrate. Based on molecular and morphological evidence we conclude that the underwater mushrooms are a new species, Psathyrella aquatica. This report adds to the biodiversity of stream fungi that degrade woody substrates. The underwater environment is a new habitat for gilled mushrooms.

  4. Assessment of the potential of state-of-the-art biomass technologies in contributing to a sustainable SADC regional mitigation energy scenario[Southern African Development Community

    Energy Technology Data Exchange (ETDEWEB)

    Yamba, F.D.; Matsika, E. [Centre for Energy, Environment and Engineering Zambia, Lusaka (Zambia)

    2003-09-01

    Southern Africa's energy supply is based on power sector collaboration - the Southern African Power Pool (SAPP). SAPP was created in 1995 through an inter-utility memorandum of understanding among 12 of the Southern African Development Community (SADC) utilities including Congo DR. The aims of SAPP are: To increase regional security of supply; To smoothen load curves; To engender economies of scale in the supply base; To increase revenue for exporting countries by opening up a ready market; To share power to meet national shortfalls and to off set temporary deficits in the medium term, and in the long term to adopt and implement power sharing as an operational strategy aimed at maximising financial and environmental benefits. Currently, SAPP has an operational installed capacity of 45.000 MW, of which 84% is thermal, predominantly coal based, which represents 79% of the total supply. 16% of the total SAPP interconnected supply is hydro, while the contribution from biomass is currently non-existent. The sugar industry in Southern Africa can significantly alter this picture. Increased competitive pressures serve as economic incentives for the sugar industry to diversify their product portfolio by investing in renewable energy applications. Of the new state-of-the-art biomass based technologies available Condensing Extraction Steam Turbine (CEST) is the most promising. Application of CEST technologies in Southern Africa will modestly contribute towards a sustainable energy supply mitigation scenario. If implemented, the contribution of bioenergy will increase from 0.5% for the baseline situation, to 2.5% in 2030 and 3.0% in 2050. This scenario will also yield global environmental benefits potential through saving of GHG reductions to 14 million tonnes CO{sub 2} in 2030 and 20 million tonnes CO{sub 2} in 2050. Furthermore, this paper produces a monogram which will assist investors in making decisions whether to invest in the Kyoto Protocols Clean Development

  5. Diet of Astyanax species (Teleostei, Characidae in an Atlantic Forest River in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Fábio Silveira Vilella

    2002-06-01

    Full Text Available Feeding habits of six species of Astyanax from river Maquiné are described. Fishes were sampled bi-monthly from November/95 to September/96 in two zones of the river. Items were identified, counted and had their abundance estimated according to a semi-quantitative scale. Frequency of occurrence, alimentary importance index (IFI values and a similarity analysis of diets for each species-river zone sample were examined. All the species were considered typically omnivorous, with insects and vegetal matter being the most important items in their diet. These species could act as seed dispersers, particularly for macrophytes. Intra-specific spatial differences were not observed in comparisons of samples from two diferent regions of the river, except for A. fasciatus. The presence of Podostemaceae macrophytes in the mid-course of the river seemed to be important both as an autochthonous food resource and as habitat for several organisms preyed by the Astyanax species.Seis espécies do gênero Astyanax, presentes no rio Maquiné, RS, foram estudadas quanto aos seus hábitos alimentares. Os exemplares foram amostrados bimensalmente de novembro de 1995 a setembro de 1996 nas zonas ritral e potamal do rio. Os itens alimentares foram identificados e quantificados de acordo com uma escala semi-quantitativa de abundância, utilizando-se para análise a frequência de ocorrência e um índice de importância alimentar para cada espécie e zona do rio. Análises multivariadas de agrupamento e ordenação foram utilizadas para comparar as dietas intra e interespecíficas. Todas as espécies foram consideradas onivoras, sendo que os itens mais importantes foram os insetos e restos de vegetais superiores. Sugere-se que as espécies estudadas possam atuar como dispersoras de sementes, particularmente para macrófitas. Diferenças espaciais intraespecíficas não foram encontradas, exceto para A. fasciatus. A presença de Podostemaceae no curso médio do rio parece

  6. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African ... search for an article by title, author/s or keywords,; and find other information sources ... Southern African Business Review; The role played by the South African ... The Basis of Distinction Between Qualitative and Quantitative Research in ...

  7. Trophic interactions of the endangered Southern river otter ( Lontra provocax) in a Chilean Ramsar wetland inferred from prey sampling, fecal analysis, and stable isotopes

    Science.gov (United States)

    Franco, Marcela; Guevara, Giovany; Correa, Loreto; Soto-Gamboa, Mauricio

    2013-04-01

    Non-invasive methodological approaches are highly recommended and commonly used to study the feeding ecology of elusive and threatened mammals. In this study, we use multiple lines of evidence to assess the feeding strategies of the endangered Southern river otter, by determining seasonal prey availability (electrofishing), analysis of undigested prey remains (spraints), and the use of stable isotopes (δ15N and δ13C) in otter spraints ( n = 262) and prey in a wetland ecosystem of southern Chile (39°49'S, 73°15'W). Fecal and isotopic analyses suggest that the otter diet is restricted to a few prey items, particularly the less-mobile, bottom-living, and larger prey such as crayfish ( Samastacus spinifrons, 86.11 %) and crabs ( Aegla spp., 32.45 %), supplemented opportunistically by cyprinids ( Cyprinus carpio, 9.55 %) and catfish ( Diplomystes camposensis, 5.66 %). The results suggest that the river otter is highly specialized in bottom foraging. Isotopic signatures of food sources and feces revealed a mid-upper trophic position for the Southern river otter, with either higher or lower δ15N values than their potential prey items. δ13C values for river otters were less enriched than their potential food resources. We suggest that due to their narrow trophic niche and possible dependence on only a few food items, this species may be highly vulnerable to the reduction in its prey populations. Finally, maintaining the ecological interactions between Southern river otters and their prey is considered a central priority for the survival of this endangered carnivore mammal.

  8. Overview of runoff of March 11, 1995, in Fortymile Wash and Amargosa River, Southern Nevada

    International Nuclear Information System (INIS)

    Beck, D.A.; Glancy, P.A.

    1996-01-01

    Yucca Mountain, approximately 120 miles northwest of Las Vegas, Nevada, is being studied by the US Department of Energy as a potential repository for long-term storage of the Nation's high-level nuclear waste. This site-characterization study includes elements pertaining to surface-water runoff, including the potential for flooding. The US Geological Survey (USGS), in cooperation with the US Department of Energy, is monitoring streamflow in southern Nevada through a network of stream-flow gaging stations and miscellaneous streamflow measurements in support of the site-characterization effort

  9. Microglanis pataxo, a new catfish from southern Bahia coastal rivers, northeastern Brazil (Siluriformes: Pseudopimelodidae)

    OpenAIRE

    Sarmento-Soares,Luisa M.; Martins-Pinheiro,Ronaldo F.; Aranda,Arion T.; Chamon,Carine C.

    2006-01-01

    A new pseudopimelodid catfish of the genus Microglanis, collected in small rivers at the lower and middle Peruípe, middle Jucuruçu and Cahy basins, in the southeastern coast of the Bahia state, is described. The new species has a comparatively high number of anal fin proximal radials, 12, shaped as thin tubes, the last one bearing a laminar extension; a pectoral fin spine with a bony point and with a smaller number of serrations on its posterior border; seven pleural ribs and a narrow head wi...

  10. Geology of the Sabie River Basalt Formation in the Southern Kruger National Park

    Directory of Open Access Journals (Sweden)

    R.J. Sweeney

    1986-11-01

    Full Text Available The Sabie River Basalt Formation (SRBF in the central Lebombo is a virtually continuous sequence of basaltic lavas some 2 500 m thick that was erupted 200 - 179 Ma ago. Flows are dominantly pahoehoe in character and vary from 2 m to 20 m in thickness. Dolerite dykes cross-cutting the basalt sequence probably represent feeders to this considerable volcanic event. Volcanological features observed within the SRBF are described. Two chemically distinct basaltic magma types are recognised, the simultaneous eruption of which presents an intriguing geochemical problem as to their origins.

  11. Flow-gauging structures in South African rivers Part 2: Calibration ...

    African Journals Online (AJOL)

    Accurate hydrological information is of paramount importance in a dry country such as South Africa. Flow measurements in rivers are complicated by the high variability of flows as well as by sediment loads and debris. It has been found necessary to modify and even substitute certain internationally accepted gauging station ...

  12. 'Beyond the rivers of Ethiopia' : Pentecostal Pan-Africanism and Ghanaian identities in the transnational domain

    NARCIS (Netherlands)

    Dijk, van R.A.

    2004-01-01

    Rev. Mensa Otabil, the founder of the International Central Gospel Church in Accra, is considered an influential representative of a new Pentecostal-inspired Pan-Africanist ideology. His book 'Beyond the Rivers of Ethiopia' lays the foundations of a Pentecostal Liberation Theology that proclaims a

  13. Terrestrial fishes: rivers are barriers to gene flow in annual fishes from the African savanna

    Czech Academy of Sciences Publication Activity Database

    Bartáková, Veronika; Reichard, Martin; Blažek, Radim; Polačik, Matej; Bryja, Josef

    2015-01-01

    Roč. 42, č. 10 (2015), s. 1832-1844 ISSN 0305-0270 R&D Projects: GA ČR(CZ) GAP506/11/0112 Institutional support: RVO:68081766 Keywords : genetic structure * geodispersal * Mozambique * Nothobranchius * phylogeography * population genetics * river morphology * vernal pool Subject RIV: EG - Zoology Impact factor: 3.997, year: 2015

  14. First report on the colony-forming freshwater ciliate Ophrydium versatile in an African river

    CSIR Research Space (South Africa)

    Oberholster, Paul J

    2010-04-01

    Full Text Available Ophrydium versatile (Müller 1786) Ehrenberg 1830 – a symbiotic ciliate that forms gelatinous colonies – is widely distributed in temperate lakes in Europe and America, but has not previously been recorded from rivers. In this paper we report...

  15. Flow-gauging structures in South African rivers Part 1: An overview

    African Journals Online (AJOL)

    2007-10-16

    Oct 16, 2007 ... to measure discharge; the gauging of stage and the translation of stage into discharge. Various ... station operational earlier than 1900 was established in 1898 on the Breede River near ..... save on concrete. If the structure is ...

  16. Geology and geophysics of the southern Raft River Valley geothermal area, Idaho, USA

    Science.gov (United States)

    Williams, Paul L.; Mabey, Don R.; Zohdy, Adel A.R.; Ackermann, Hans D.; Hoover, Donald B.; Pierce, Kenneth L.; Oriel, Steven S.

    1976-01-01

    The Raft River valley, near the boundary of the Snake River plain with the Basin and Range province, is a north-trending late Cenozoic downwarp bounded by faults on the west, south, and east. Pleistocene alluvium and Miocene-Pliocene tuffaceous sediments, conglomerate, and felsic volcanic rocks aggregate 2 km in thickness. Large gravity, magnetic, and total field resistivity highs probably indicate a buried igneous mass that is too old to serve as a heat source. Differing seismic velocities relate to known or inferred structures and to a suspected shallow zone of warm water. Resistivity anomalies reflect differences of both composition and degree of alteration of Cenozoic rocks. Resistivity soundings show a 2 to 5 ohm·m unit with a thickness of 1 km beneath a large part of the valley, and the unit may indicate partly hot water and partly clayey sediments. Observed self-potential anomalies are believed to indicate zones where warm water rises toward the surface. Boiling wells at Bridge, Idaho are near the intersection of north-northeast normal faults which have moved as recently as the late (?) Pleistocene, and an east-northeast structure, probably a right-lateral fault. Deep circulation of ground water in this region of relatively high heat flow and upwelling along faults is the probable cause of the thermal anomaly.

  17. Sediment accumulation rate and radiological characterisation of the sediment of Palmones River estuary (southern of Spain)

    International Nuclear Information System (INIS)

    Rubio, L.; Linares-Rueda, A.; Duenas, C.; Fernandez, M.C.; Clavero, V.; Niell, F.X.; Fernandez, J.A.

    2003-01-01

    Chemical analyses and radioecological methods were combined in order to estimate the sediment accumulation rate in the upper 20 cm depth of the Palmones River estuary. Organic matter, total carbon, C:N and 137 Cs vertical profiles showed changes at 13 cm depth. These changes could be associated with the decrease in river input since 1987 when a dam situated in the upper part of the estuary started to store water. Using 1987 as reference to date the sediment, accumulation rate was 1.2 cm yr -1 . As alternative method, two layer model of 210 Pb xs vertical distribution showed a sedimentation rate of 0.7 cm yr -1 with a surface mixing layer of 7 cm thickness. The high ammonium, potassium and sodium content in pore water and the strong correlation between 137 Cs activities and organic matter in dry sediment suggests that 137 Cs (the only anthropogenic product detected) is mainly accumulated in the estuary associated with the particulate organic material from the catchment area

  18. Ephemeral stream reaches preserve the evolutionary and distributional history of threespine stickleback in the Santa Clara and Ventura River watersheds of southern California

    Science.gov (United States)

    Richmond, Jonathan Q.; Jacobs, David K.; Backlin, Adam R.; Swift, Camm C.; Dellith, Chris; Fisher, Robert N.

    2015-01-01

    Much remains to be understood about the evolutionary history and contemporary landscape genetics of unarmored threespine stickleback in southern California, where populations collectively referred to as Gasterosteus aculeatus williamsoni have severely declined over the past 70+ years and are now endangered. We used mitochondrial sequence and microsatellite data to assess the population genetics and phylogeography of unarmored populations sampled immediately downstream from the type locality of G. a. williamsoni in the upper Santa Clara River, and assessed their distinctiveness with respect to low-armor populations in the downstream sections of the river and the adjacent Ventura River. We also characterized the geographic limits of different plate morphs and evaluated the congruence of those boundaries with barriers to dispersal in both river systems and to neutral genetic variation. We show substantial population structuring within the upper reach of the Santa Clara River, but little partitioning between the lower Santa Clara and Ventura Rivers—we attribute these patterns to different ancestry between spatially subdivided populations within the same drainage, a predominance of downstream gene flow, and ability for coastal dispersal between the Santa Clara and Ventura Rivers. We also show that alleles from introduced low-plate stock have infiltrated a native population in at least one upper Santa Clara River tributary, causing this formerly unarmored population to become gradually low-plated over a 30 + year time period. Measures of genetic diversity, census surveys, and severe habitat disturbance all indicate that unarmored stickleback near the type locality are currently at high risk of extinction.

  19. Assessing sedimentation rates at Usumacinta and Grijalva river basin (Southern Mexico) using OSL and suspended sediment load analysis: A study from the Maya Classic Period

    Science.gov (United States)

    Munoz-Salinas, E.; Castillo, M.; Sanderson, D.; Kinnaird, T.; Cruz-Zaragoza, E.

    2013-12-01

    Studying sedimentation rates on floodplains is key to understanding environmental changes occurred through time in river basins. The Usumacinta and Grijalva rivers flow most of their travel through the southern part of Mexico, forming a large river basin, crossing the states of Chiapas and Tabasco. The Usumacinta-Grijalva River Basin is within the 10 major rivers of North America, having a basin area of ~112 550 km2. We use the OSL technique for dating two sediment profiles and for obtaining luminescence signals in several sediment profiles located in the streambanks of the main trunk of the Usumacinta and Grijalva rivers. We also use mean annual values of suspended sediment load spanning ~50 years to calculate the sedimentation rates. Our OSL dating results start from the 4th Century, when the Maya Civilization was at its peak during the Classic Period. Sedimentation rates show a notable increase at the end of the 19th Century. The increase of the sedimentation rates seems to be related to changes in land uses in the Sierra Madre de Chiapas and Altos de Chiapas, based on deforestation and land clearing for developing new agrarian and pastoral activities. We conclude that the major environmental change in the basin of the Usumacinta and Grijalva Rivers since the Maya Classic Period was generated since the last Century as a result of an intense anthropogenic disturbance of mountain rain forest in Chiapas.

  20. Impact of city effluents on water quality of Indus River: assessment of temporal and spatial variations in the southern region of Khyber Pakhtunkhwa, Pakistan.

    Science.gov (United States)

    Khan, Ilham; Khan, Azim; Khan, Muhammad Sohail; Zafar, Shabnam; Hameed, Asma; Badshah, Shakeel; Rehman, Shafiq Ur; Ullah, Hidayat; Yasmeen, Ghazala

    2018-04-04

    The impact of city effluents on water quality of Indus River was assessed in the southern region of Khyber Pakhtunkhwa, Pakistan. Water samples were collected in dry (DS) and wet (WS) seasons from seven sampling zones along Indus River and the physical, bacteriological, and chemical parameters determining water quality were quantified. There were marked temporal and spatial variations in the water quality of Indus River. The magnitude of pollution was high in WS compared with DS. The quality of water varied across the sampling zones, and it greatly depended upon the nature of effluents entering the river. Water samples exceeded the WHO permissible limits for pH, EC, TDS, TS, TSS, TH, DO, BOD, COD, total coliforms, Escherichia coli, Ca 2+ , Mg 2+ , NO 3 - , and PO 4 2- . Piper analysis indicated that water across the seven sampling zones along Indus River was alkaline in nature. Correlation analyses indicated that EC, TDS, TS, TH, DO, BOD, and COD may be considered as key physical parameters, while Na + , K + , Ca 2+ , Mg 2+ , Cl - , F - , NO 3 - , PO 4 2- , and SO 4 2- as key chemical parameters determining water quality, because they were strongly correlated (r > 0.70) with most of the parameters studied. Cluster analysis indicated that discharge point at Shami Road is the major source of pollution impairing water quality of Indus River. Wastewater treatment plants must be installed at all discharge points along Indus River for protecting the quality of water of this rich freshwater resource in Pakistan.

  1. Bioavailability of pollutants sets risk of exposure to biota and human population in reservoirs from Iguaçu River (Southern Brazil).

    Science.gov (United States)

    Yamamoto, F Y; Pereira, M V M; Lottermann, E; Santos, G S; Stremel, T R O; Doria, H B; Gusso-Choueri, P; Campos, S X; Ortolani-Machado, C F; Cestari, M M; Neto, F Filipak; Azevedo, J C R; Ribeiro, C A Oliveira

    2016-09-01

    The Iguaçu River, located at the Southern part of Brazil, has a great socioeconomic and environmental importance due to its high endemic fish fauna and its potential to generate hydroelectric power. However, Iguaçu River suffers intense discharge of pollutants in the origin of the river. In a previous report, the local environmental agency described water quality to improve along the river course. However, no study with integrated evaluation of chemical analysis and biological responses has been reported so far for the Iguaçu River. In the current study, three different Brazilian fish species (Astyanax bifasciatus, Chrenicicla iguassuensis, and Geophagus brasiliensis) were captured in the five cascading reservoirs of Iguaçu River for a multi-biomarker study. Chemical analysis in water, sediment, and muscle indicated high levels of bioavailable metals in all reservoirs. Polycyclic aromatic hydrocarbons (PAHs) were detected in the bile of the three fish species. Integration of the data through a FA/PCA analysis demonstrated the poorest environmental quality of the reservoir farthest from river's source, which is the opposite of what has been reported by the environmental agency. The presence of hazardous chemicals in the five reservoirs of Iguaçu River, their bioaccumulation in the muscle of fish, and the biological responses showed the impacts of human activities to this area and did not confirm a gradient of pollution between the five reservoirs, from the source toward Iguaçu River's mouth. Therefore, diffuse source of pollutants present along the river course are increasing the risk of exposure to biota and human populations.

  2. Southern San Andreas Fault Slip History Refined Using Pliocene Colorado River Deposits in the Western Salton Trough

    Science.gov (United States)

    Dorsey, R. J.; Bennett, S. E. K.; Housen, B. A.

    2016-12-01

    Tectonic reconstructions of Pacific-North America plate motion in the Salton Trough region (Bennett et al., 2016) are constrained by: (1) late Miocene volcanic rocks that record 255 +/-10 km of transform offset across the northern Gulf of California since 6 Ma (average 42 mm/yr; Oskin and Stock, 2003); and (2) GPS data that show modern rates of 50-52 mm/yr between Pacific and North America plates, and 46-48 mm/yr between Baja California (BC) and North America (NAM) (Plattner et al., 2007). New data from Pliocene Colorado River deposits in the Salton Trough provide an important additional constraint on the geologic history of slip on the southern San Andreas Fault (SAF). The Arroyo Diablo Formation (ADF) in the San Felipe Hills SW of the Salton Sea contains abundant cross-bedded channel sandstones deformed in the dextral Clark fault zone. The ADF ranges in age from 4.3 to 2.8 Ma in the Fish Creek-Vallecito basin, and in the Borrego Badlands its upper contact with the Borrego Formation is 2.9 Ma based on our new magnetostratigraphy. ADF paleocurrent data from a 20-km wide, NW-oriented belt near Salton City record overall transport to the SW (corrected for bedding dip, N=165), with directions ranging from NW to SE. Spatial domain analysis reveals radial divergence of paleoflow to the: W and NW in the NW domain; SW in the central domain; and S in the SE domain. Data near Borrego Sink, which restores to south of Salton City after removing offset on the San Jacinto fault zone, show overall transport to the SE. Pliocene patterns of radial paleoflow divergence strongly resemble downstream bifurcation of fluvial distributary channels on the modern Colorado River delta SW of Yuma, and indicate that Salton City has translated 120-130 km NW along the SAF since 3 Ma. We propose a model in which post-6 Ma BC-NAM relative motion gradually accelerated to 50 mm/yr by 4 Ma, continued at 50 mm/yr from 4-1 Ma, and decreased to 46 mm/yr from 1-0 Ma (split equally between the SAF and

  3. Microglanis pataxo, a new catfish from southern Bahia coastal rivers, northeastern Brazil (Siluriformes: Pseudopimelodidae

    Directory of Open Access Journals (Sweden)

    Luisa M. Sarmento-Soares

    Full Text Available A new pseudopimelodid catfish of the genus Microglanis, collected in small rivers at the lower and middle Peruípe, middle Jucuruçu and Cahy basins, in the southeastern coast of the Bahia state, is described. The new species has a comparatively high number of anal fin proximal radials, 12, shaped as thin tubes, the last one bearing a laminar extension; a pectoral fin spine with a bony point and with a smaller number of serrations on its posterior border; seven pleural ribs and a narrow head width. We provide information on the external morphology and also on some osteological features for the new species. A key to species is presented for the coastal drainages between Rio de Janeiro and Bahia states.

  4. The Aquatic And Marshy Flora Of The Lotru River Basin (Southern Carpathians, Romania

    Directory of Open Access Journals (Sweden)

    Drăgulescu Constantin

    2014-10-01

    Full Text Available The present paper continues the series of floristic inventories of the main Romanian rivers in the Carpathian Mountains (from which have been published those of Mureş, Sadu, Olt, Someş, Criş, Târnave, Tisa. In this work the author lists 204 plant taxa (hydrophilic, meso-hygrophilic and hygrophilic identified by the author or by other botanists in the Lotru Valley basin. Noted for each species were life form, floral element, ecological preferences for humidity (U, temperature (T, soil reaction (R, corology and coenology. Bibliographical sources are coded with numbers (see the references at the end of the paper. The sign “!” indicates that the author has seen the plant in that locality.

  5. Risk assessment of Giardia in rivers of southern China based on continuous monitoring

    Institute of Scientific and Technical Information of China (English)

    Wei An; Dongqing Zhang; Shumin Xiao; Jianwei Yu; Min Yang

    2012-01-01

    The occurrence and risks of Giardia in China have been unclear to date,which has made it difficult to properly manage source water as well as to create reasonable drinking water standards.The levels of Giardia in river networks of several cities in Zhejiang Province,China were found to be in the range of 0-5 oocysts/10 L in the rainy season in 2008.The mortality due to Giardia infection for people in this region was calculated to be from 0 to 1.95 × 10-s persons using a conditional probability equation.Based on multiple unboiled water intake routes,the disability-adjusted life years (DALYs) due to Giardia infection for people who consumed conventionally treated water was 0.625 (95% CI:0.137-2.05) per 105 persons,with the symptom of hospitalization making the highest contribution to total DALYs (0.56 per 105 persons; 95% CI:0.122-1.84).The DALYs decreased to 0.425 (95% CI:0.137-2.05) per 105 persons per year for those consuming water treated with advanced technology.These values were lower than the acceptable risk (1.97 × 10-5 DALYs per year).This study revealed the risk of Giardia infection to the people in river networks of Zhejiang Province for the first time,and provides a method to evaluate the risk of Giardia infection.The results are useful for the modification of drinking water quality standards based on cost-benefit analysis.

  6. The History and Future of the Southern Bible Institute: A Post-Secondary School of Biblical Studies for African Americans

    Science.gov (United States)

    Cooks, Michael

    2010-01-01

    The United States of America has a long history in higher education, but one area of its history not exhausted through research involves higher education for African Americans. Specifically, higher education for African Americans in the area of theology or biblical studies presents numerous opportunities for further research. Soon after the…

  7. Primary sink and source of geogenic arsenic in sedimentary aquifers in the southern Choushui River alluvial fan, Taiwan

    International Nuclear Information System (INIS)

    Lu, Kuang-Liang; Liu, Chen-Wuing; Wang, Sheng-Wei; Jang, Cheng-Shin; Lin, Kao-Hung; Liao, Vivian Hsiu-Chuan; Liao, Chung-Min; Chang, Fi-John

    2010-01-01

    This work characterized the sink and source/mobility of As in the As-affected sedimentary aquifers of the southern Choushui River alluvial fan, central Taiwan. Major mineral phases and chemical components were determined by XRD and X-ray photoelectron spectroscopy (XPS). The partitioning of As and Fe among cores were determined by sequential extraction. Based on XPS results, the primary forms of Fe were hematite, goethite and magnetite. Sequential extraction data and the XRF analysis indicated that Fe oxyhydroxides and sulfides were likely to be the major sinks of As, particularly in the distal-fan. Furthermore, Fe oxyhydroxides retained higher As contents than As-bearing sulfides. The reductive dissolution of Fe oxyhydroxides, which accompanied high levels of HCO 3 - and NH 4 + concentrations, was likely the principal release mechanism of As into groundwater in this area. The dual roles of Fe oxyhydroxides which are governed by the local redox condition act as a sink and source in the aquifer. Ionic replacement by PO 4 3- and HCO 3 - along with seasonal water table fluctuation, caused by monsoons and excessive pumping, contributed specific parts of As in the groundwater. The findings can be used to account for the inconsistency between Fe and As concentrations observed in groundwater.

  8. Detecting the transport barriers in the Pearl River estuary, Southern China with the aid of Lagrangian coherent structures

    Science.gov (United States)

    Wei, Xing; Zhan, Haigang; Cai, Shuqun; Zhan, Weikang; Ni, Peitong

    2018-05-01

    Knowledge of horizontal transport pathways is important for the protection of the marine ecosystem in coastal areas. In this paper, we develop a 3D model to simulate hydrodynamics and particle transport in the Pearl River Estuary (PRE), Southern China, to study the barriers to transport in the PRE. Specifically, we use the flow velocity produced by the model to locate Lagrangian coherent structures (LCSs) hidden in ocean surface currents. Our findings show that a remarkable LCS begins upstream near the Humen inlet, extends to the Wanshan Islands via Neilingding Island, and can act as a transport barrier in the estuary. This LCS appeared 1-2 h after high tide and was persistent for 6-7 h during every ebb tide. Particles released on the west side of the LCS moved downstream, exited the estuary by Daxi Channel, and seldom spread to the east side, especially the Hong Kong Sea area. An analysis of several scenarios suggested that the formation of this LCS was due to topography restrictions and tidal forces.

  9. River-Basin Politics and the Rise of Ecological and Transnational Democracy in Southeast Asia and Southern Africa

    Directory of Open Access Journals (Sweden)

    Chris Sneddon

    2008-06-01

    Full Text Available In recent years, debates over 'deliberative', 'transnational' and 'ecological' democracy have proliferated, largely among scholars engaged in discussions of modernisation, globalisation and political identity. Within this broad context, scholars and practitioners of environmental governance have advanced the argument that a democratic society will produce a more environmentally conscious society. We want to make a volte-face of this argument and ask: to what extent does engagement with environmental politics and, specifically, water politics, contribute to processes of democratisation? After reviewing some of the contributions to debates over 'ecological' and 'transnational' democracy, we explore this question within the context of conflicts over river-basin development in Southeast Asia and southern Africa. We argue that there are multiple pathways to democratisation and that, in some cases, the environment as a political issue does constitute a significant element of democratisation. But notions of 'ecological' and 'transnational' democracy must embody how both 'environment' and 'the transnational', as mobilised by specific social movements in specific historical and geographical circumstances, are politically constructed.

  10. Pattern variation of fish fingerling abundance in the Na Thap Tidal river of Southern Thailand: 2005-2015

    Science.gov (United States)

    Donroman, T.; Chesoh, S.; Lim, A.

    2018-04-01

    This study aimed to investigate the variation patterns of fish fingerling abundance based on month, year and sampling site. Monthly collecting data set of the Na Thap tidal river of southern Thailand, were obtained from June 2005 to October 2015. The square root transformation was employed for maintaining the fingerling data normality. Factor analysis was applied for clustering number of fingerling species and multiple linear regression was used to examine the association between fingerling density and year, month and site. Results from factor analysis classified fingerling into 3 factors based on saline preference; saline water, freshwater and ubiquitous species. The results showed a statistically high significant relation between fingerling density, month, year and site. Abundance of saline water and ubiquitous fingerling density showed similar pattern. Downstream site presented highest fingerling density whereas almost of freshwater fingerling occurred in upstream. This finding confirmed that factor analysis and the general linear regression method can be used as an effective tool for predicting and monitoring wild fingerling density in order to sustain fish stock management.

  11. MOSSES AS BIOINDICATORS OF AIR POLLUTION ALONG AN URBAN–AGRICULTURAL TRANSECT IN THE CREDIT RIVER WATERSHED, SOUTHERN ONTARIO, CANADA

    Directory of Open Access Journals (Sweden)

    P. Cowden

    2015-04-01

    Full Text Available The activities associated with urbanization, such as vehicular traffic and industrial processes, lead to elevated emissions of atmospheric pollutants. Measuring the spatial extent of these pollutants is pivotal to identifying areas of concern and assessing mitigation measures. The objective of this study was to evaluate the relative deposition of heavy metals and nitrogen using moss species along an urban–agricultural transition in the Credit River Watershed, southern Ontario. Thirteen species of moss were collected from Sugar Maple (Acer saccharum dominated forest stands across the study area, with only one moss species (Atrichum altercristatum commonly occurring. Heavy metal concentrations were variable between species; the Coefficient of Variation (CV for the majority of metals (Al, V, Cr, Fe, Ni, As, Sb and Pb was greater than ~50% across species. Nonetheless, metals exhibited similar trends, with the highest concentrations for Fe, followed by Al > Zn > Cu > Pb > Cr > Ni > V > As > Cd > Sb > Hg across species. Heavy metal concentrations in Atrichum altercristatum exhibited lower variability between sites, with CV < 33% for most metals (Cu, Zn, As, Cd, Sb, Pb and Hg. Further, many metal concentrations were strongly correlated (e.g., Al, V, Cr, Fe, and As; r ≤ 0.90 suggesting common emission sources, such as wind blown dust from agricultural activities or vehicular traffic, both predominant throughout the watershed.

  12. Evaluating LSM-Based Water Budgets Over a West African Basin Assisted with a River Routing Scheme

    Science.gov (United States)

    Getirana, Augusto C. V.; Boone, Aaron; Peugeot, Christophe

    2014-01-01

    Within the framework of the African Monsoon Multidisciplinary Analysis (AMMA) Land Surface Model Intercomparison Project phase 2 (ALMIP-2), this study evaluates the water balance simulated by the Interactions between Soil, Biosphere, and Atmosphere (ISBA) over the upper Oum River basin, in Benin, using a mesoscale river routing scheme (RRS). The RRS is based on the nonlinear Muskingum Cunge method coupled with two linear reservoirs that simulate the time delay of both surface runoff and base flow that are produced by land surface models. On the basis of the evidence of a deep water-table recharge in that region,a reservoir representing the deep-water infiltration (DWI) is introduced. The hydrological processes of the basin are simulated for the 2005-08 AMMA field campaign period during which rainfall and stream flow data were intensively collected over the study area. Optimal RRS parameter sets were determined for three optimization experiments that were performed using daily stream flow at five gauges within the basin. Results demonstrate that the RRS simulates stream flow at all gauges with relative errors varying from -22% to 3% and Nash-Sutcliffe coefficients varying from 0.62 to 0.90. DWI varies from 24% to 67% of the base flow as a function of the sub-basin. The relatively simple reservoir DWI approach is quite robust, and further improvements would likely necessitate more complex solutions (e.g., considering seasonality and soil type in ISBA); thus, such modifications are recommended for future studies. Although the evaluation shows that the simulated stream flows are generally satisfactory, further field investigations are necessary to confirm some of the model assumptions.

  13. Evaluation of genotoxicity and cytotoxicity of water samples from the Sinos River Basin, southern Brazil

    Directory of Open Access Journals (Sweden)

    E Bianchi

    Full Text Available Some water bodies in the Sinos River Basin (SRB have been suffering the effects of pollution by residential, industrial and agroindustrial wastewater. The presence of cytotoxic and genotoxic compounds could compromise the water quality and the balance of these ecosystems. In this context, the research aimed to evaluate the genotoxicity and cytotoxicity of the water at four sites along the SRB (in the cities of Santo Antônio da Patrulha, Parobé, Campo Bom and Esteio, using bioassays in fish and cell culture. Samples of surface water were collected and evaluated in vitro using the Astyanax jacuhiensis fish species (micronucleus test and comet assay and the Vero lineage of cells (comet assay and cytotoxicity tests, neutral red - NR and tetrazolium MTT. The micronucleus test in fish showed no significant differences between the sampling sites, and neither did the comet assay and the MTT and NR tests in Vero cells. The comet assay showed an increase in genetic damage in the fish exposed to water samples collected in the middle and lower sections of the basin (Parobé, Campo Bom and Esteio when compared to the upper section of the basin (Santo Antônio da Patrulha. The results indicate contamination by genotoxic substances starting in the middle section of the SRB.

  14. Hydrogeology along the southern boundary of the Hanford Site between the Yakima and Columbia Rivers, Washington

    International Nuclear Information System (INIS)

    Liikala, T.L.

    1994-09-01

    US Department of Energy (DOE) operations at the Hanford Site, located in southeastern Washington, have generated large volumes of hazardous and radioactive wastes since 1944. Some of the hazardous wastes were discharged to the ground in the 1100 and 3000 Areas, near the city of Richland. The specific waste types and quantities are unknown; however, they probably include battery acid, antifreeze, hydraulic fluids, waste oils, solvents, degreasers, paints, and paint thinners. Between the Yakima and Columbia rivers in support of future hazardous waste site investigations and ground-water and land-use management. The specific objectives were to collect and review existing hydrogeologic data for the study area and establish a water-level monitoring network; describe the regional and study area hydrogeology; develop a hydrogeologic conceptual model of the unconfined ground-water flow system beneath the study area, based on available data; describe the flow characteristics of the unconfined aquifer based on the spatial and temporal distribution of hydraulic head within the aquifer; use the results of this study to delineate additional data needs in support of future Remedial Investigation/Feasibility Studies (RI/FS), Fate and Transport modeling, Baseline Risk Assessments (BRA), and ground-water and land-use management

  15. Amazon river basin evapotranspiration and its influence on the rainfall in southern Brazil

    Science.gov (United States)

    Folegatti, M. V.; Wolff, W.

    2017-12-01

    Amazon river basin (ARB) presents a positive water balance, i.e. the precipitation is higher than evapotranspiration. Regarding the regional circulation, ARB evapotranspiration represents an important source of humidity for the South of Brazil. Thus, the aim of this work is to answer the question: how much is the correlation between ARB evapotranspiration and rainfall in South of Brazil? The shapefiles data of ARB and countries/states boundary were obtained through the Oak Ridge National Laboratory (ORNL) and Instituto Brasileiro de Geografia e Estatística (IBGE), respectively. According to rasters data, the precipitation was obtained from study of Numerical Terradynamic Simulation Group (NTSG) for images of Moderate Resolution Imaging Spectroradiometer (MODIS), under code MOD16A2, whereas rasters data for evapotranspiration were obtained from National Aeronautics and Space Administration (NASA) by Tropical Rainfall Measuring Mission Multi-Satellite Precipitation Analysis (TMPA), under code 3B43_V7. The products MOD16A2 and 3B43_V7 have a respective spatial resolution of 0.5º and 0.25º, and a monthly temporal resolution from January/2000 to December/2014. For ARB and South region of Brazil was calculated the mean evapotranspiration and mean precipitation through the pixels within of the respective polygons. To answer the question of this work was performed the cross-correlation analysis between these time series. We observed the highest value for the lag that corresponds the begin of spring (October), being 0.3 approximately. As a result, the mean precipitation on South region of Brazil during spring and summer was in the order of 15% to 30 %, explained by ARB evapotranspiration. For this reason, the maintenance of ARB is extremely important for water resource grant in South of Brazil.

  16. Vector bionomics and malaria transmission in the Upper Orinoco River, Southern Venezuela

    Directory of Open Access Journals (Sweden)

    Magda Magris

    2007-06-01

    Full Text Available A longitudinal epidemiological and entomological study was carried out in Ocamo, Upper Orinoco River, between January 1994 and February 1995 to understand the dynamics of malaria transmission in this area. Malaria transmission occurs throughout the year with a peak in June at the beginning of the rainy season. The Annual Parasite Index was 1,279 per 1,000 populations at risk. Plasmodium falciparum infections accounted for 64% of all infections, P. vivax for 28%, and P. malariae for 4%. Mixed P. falciparum/P. vivax infections were diagnosed in 15 people representing 4% of total cases. Children under 10 years accounted for 58% of the cases; the risk for malaria in this age group was 77% higher than for those in the greater than 50 years age group. Anopheles darlingi was the predominant anopheline species landing on humans indoors with a biting peak between midnight and dawn. A significant positive correlation was found between malaria monthly incidence and mean number of An. darlingi caught. There was not a significant relationship between mean number of An. darlingi and rainfall or between incidence and rainfall. A total of 7295 anophelines were assayed by ELISA for detection of Plasmodium circumsporozoite (CS protein. Only An. darlingi (55 was positive for CS proteins of P. falciparum (0.42%, P. malariae (0.25%, and P. vivax-247 (0.1%. The overall estimated entomological inoculation rate was 129 positive bites/person/year. The present study was the first longitudinal entomological and epidemiological study conducted in this area and set up the basic ground for subsequent intervention with insecticide-treated nets.

  17. INFLUENCE OF EXTREME DISCHARGE ON RESTORATION WORKS IN MOUNTAIN RIVER – A CASE STUDY OF THE KRZCZONÓWKA RIVER (SOUTHERN POLAND

    Directory of Open Access Journals (Sweden)

    Anna Lenar-Matyas

    2015-06-01

    Full Text Available The research was conducted on the Krzczonówka River channel, one of the gravel-bedded, regulated mountain river in Polish Carpathians. The main morphological and ecological problem of the river was lack of sediment and channel downcutting. The area is currently associated with an on-going project called “the Upper Raba River Spawning Grounds”. Lowering of an existing debris dam on Krzczonówka River is a part of the project. In 2013 twelve artificial riffles have been created by heaping up stones at points within the segment of the river channel below the debris dam. The riffles are to introduce variety to the longitudinal profile of the river and to reduce the river’s slope. Consequently, these are to decrease sediment transport and to prevent further deepening of the river channel. Post-project monitoring of river restoration works is conducted to determine channel changes and development. In May, 2014, extreme flooding occurred, which caused unexpected changes in channel development. This paper describes maintenance work performed in the riverbed of the Krzczonówka River. Observations and calculations concerning changes in conditions of water flow and sediment transport are also presented. The main purpose is to characterize the influence of an extreme flow event on morphology and functioning of the recently restored gravel-bed river.

  18. Computational analysis of candidate disease genes and variants for Salt-sensitive hypertension in indigenous Southern Africans

    KAUST Repository

    Tiffin, Nicki; Meintjes, Ayton; Ramesar, Rajkumar; Bajic, Vladimir B.; Rayner, Brian

    2010-01-01

    appears more prevalent in people of indigenous African origin. The underlying genetics of salt-sensitive hypertension, however, are poorly understood. In this study, computational methods including text- and data-mining have been used to select

  19. Impact of emission control on regional air quality in the Pearl Delta River region, southern China

    Science.gov (United States)

    Wang, N.; Xuejiao, D.

    2017-12-01

    The Pearl River Delta (PRD) in China has been suffering from air quality issues and the government has implemented a series of strategies in controlling emissions. In an attempt to provide scientific support for improving air quality, the paper investigates the concerning past-to-present air quality data and assesses air quality resulting from emission control. Statistical data revealed that energy consumption doubled from 2004 to 20014 and vehicle usage increased significantly from 2006 to 2014. Due to the effect of control efforts, primary emission of SO2, NOx and PM2.5 decreased resulting in ambient concentrations of SO2, NO2 and PM10 decreased by 66%, 20% and 24%, respectively. However, O3 increased 19% because of the increase of VOC emission. A chemical transport model, the Community Multi-scale Air Quality, was employed to evaluate the responses of nitrate, ammonium, SOA, PM2.5 and O3 to changes in NOx, VOC and NH3 emissions. Three scenarios, a baseline scenario, a CAP scenario (control strength followed as past tendency), and a REF scenario (strict control referred to latest policy and plans), were conducted to investigate the responses and mechanisms. NOx controlling scenarios showed that NOx, nitrate and PM2.5 reduced by 1.8%, 0.7% and 0.2% under CAP and reduced by 7.2%, 1.8% and 0.3% under REF, respectively. The results indicated that reducing NOx emission caused the increase of atmospheric oxidizability, which might result in a compensation of PM2.5 due to the increase of nitrate or sulfate. NH3 controlling scenarios showed that nitrate was sensitive to NH3 emission in PRD, with nitrate decreased by 0 - 10.6% and 0 - 48% under CAP and REF, respectively. Since controlling NH3 emissions not only reduced ammonium but also significantly reduced nitrate, the implement of NH3 controlling strategy was highly suggested. The VOC scenarios revealed that though SOA was not the major component of PM2.5, controlling VOC emission might take effect in southwestern PRD

  20. Adaptive response among residents of the Techa River area and other localities in the Southern Urals

    International Nuclear Information System (INIS)

    Khudyakoval, O. I.; Akleyevl, V.; Alenschenki, A. V.; Gotib, V. J.; Kudriashova, O. V.; Semenova, I. P.; Serebryanyi, A. M.; Pelevina, I. I.

    2004-01-01

    Adaptive response was investigated in a population of adult residents of contaminated and uncontaminated villages on the Techa River. Blood lymphocytes were cultivated after addition of PHA and the cytokinetic block with cytochalasin B. the frequency of cells with imcronuclei (MN) was scored in (1000-2000) bi-nucleated cells. The adaptive response (AR) was determined for each individual as a ratio of cells with MN after irradiation at an adaptive dose (of 0.05 Gy) and at a challenge dose (of 1.0 Gy) 5 h later, to cells with MN after a single irradiation at the dose of 1.0 Gy. The criterion of 2 for the calculation of statistical significance was used p<0.05. The analysis of all data obtained shows that the spontaneous level of cells with MN is, on the average, the same in chronically exposed people and people living in uncontaminated area in the same socio-economic and climatic conditions (control group), but the individual variability was found to be increased in the exposed group. It is important to note that there is a correlation between the frequency of cells with MN and the internal exposure dose (to the red bone marrow). The level of cells with MN after irradiation in the dose of 1.0 Gy is characterised by high individual variability in irradiated population; and there is a correlation between the spontaneous frequency of cells with; MN and the radiosensitivity observed. The main difference between the exposed and control population is manifested by different numbers of peoples with significant AR. In the exposed group a lower number of individuals have a significant AR; on the other hand, a higher number of exposed residents have shown an increased radiosensitivity after adaptive irradiation at the dose of 0.05 Gy. In chronically exposed population a high degree of individual variability is observed, especially after acute irradiation in the dose of 1.0 gy. It was noted that after irradiation in the dose of 0.05 Gy the number of people with significant AR

  1. Source apportionment and health effect of NO_x over the Pearl River Delta region in southern China

    International Nuclear Information System (INIS)

    Lu, Xingcheng; Yao, Teng; Li, Ying; Fung, Jimmy C.H.; Lau, Alexis K.H.

    2016-01-01

    As one of the most notorious atmospheric pollutants, NO_x not only promotes the formation of ozone but also has adverse health effects on humans. It is therefore of great importance to study the sources of NO_x and its effects on human health. The Comprehensive Air Quality Model (CAMx) modeling system and ozone source apportionment technology (OSAT) were used to study the contribution of NO_x from different emission sources over southern China. The results indicate that heavy duty diesel vehicles (HDDVs) and industrial point sources are the two major local NO_x sources, accounting for 30.8% and 18.5% of local NO_x sources, respectively. In Hong Kong, marine emissions contributed around 43.4% of local NO_x in 2011. Regional transport is another important source of this pollutant, especially in February and November, and it can contribute over 30% of ambient NO_x on average. Power plant point emission is an significant regional source in Zhuhai, Zhongshan and Foshan. The total emission sources are estimated to cause 2119 (0–4405) respiratory deaths and 991 (0–2281) lung cancer deaths due to long-term exposure to NO_x in the Pearl River Delta region. Our results suggest that local governments should combine their efforts and vigorously promote further reduction of NO_x emissions, especially for those sources that make a substantial contribution to NO_x emissions and affect human health: HDDV, LDGV, industrial point sources and marine sources. - Highlights: • WRF-CAMx modeling system with OSAT was used to study the source of NO_x over Pearl River Delta region in China. • The results indicated that local emission and regional transportation are important contributors for NO_x in this region. • Heavy duty diesel vehicle, marine emission and industrial point source are three important contribution sectors. • Long-term exposure to NO_x is estimated to cause 2119 respiratory deaths and 991 lung cancer deaths in PRD during 2011. - Result indicated that heavy duty

  2. Microbial flora in organic honey samples of africanized honeybees from Parana river islands

    Directory of Open Access Journals (Sweden)

    Maria Josiane Sereia

    2011-06-01

    Full Text Available The purpose of this study was to verify and compare the main contamination sources and the hygienic/sanitary conditions of organic honey samples of Apis mellifera from Parana River islands. Thirty-three (33 samples were analyzed between January 2005 and August 2006. Eleven (11 samples were collected by beekeepers and twenty-two (22 samples were collected and processed in accordance with ideal personal hygiene norms and good manufacturing practices. The samples underwent microbiological analysis in search of coliforms at 35 ºC and 45 ºC, as well as fungi enumeration analysis. As for fungi counting, the samples harvested by beekeepers showed values above the maximum established by Resolution nº 15/94 of Common Market Group - Mercosul. The results showed that secondary contamination sources are responsible for the reduction of organic honey quality.

  3. Distribution and pollution, toxicity and risk assessment of heavy metals in sediments from urban and rural rivers of the Pearl River delta in southern China.

    Science.gov (United States)

    Xiao, Rong; Bai, Junhong; Huang, Laibin; Zhang, Honggang; Cui, Baoshan; Liu, Xinhui

    2013-12-01

    Sediments were collected from the upper, middle and lower reaches of both urban and rural rivers in a typical urbanization zone of the Pearl River delta. Six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) were analyzed in all sediment samples, and their spatial distribution, pollution levels, toxicity and ecological risk levels were evaluated to compare the characteristics of heavy metal pollution between the two rivers. Our results indicated that the total contents of the six metals in all samples exceeded the soil background value in Guangdong province. Based on the soil quality thresholds of the China SEPA, Cd levels at all sites exceeded class III criteria, and other metals exhibited pollution levels exceeding class II or III criteria at both river sites. According to the sediment quality guidelines of the US EPA, all samples were moderately to heavily polluted by Cr, Cu, Ni, Pb and Zn. Compared to rural river sites, urban river sites exhibited heavier pollution. Almost all sediment samples from both rivers exhibited moderate to serious toxicity to the environment, with higher contributions from Cr and Ni. A "hot area" of heavy metal pollution being observed in the upper and middle reaches of the urban river area, whereas a "hot spot" was identified at a specific site in the middle reach of the rural river. Contrary metal distribution patterns were also observed along typical sediment profiles from urban and rural rivers. However, the potential ecological risk indices of rural river sediments in this study were equal to those of urban river sediments, implying that the ecological health issues of the rivers in the undeveloped rural area should also be addressed. Sediment organic matter and grain size might be important factors influencing the distribution profiles of these heavy metals.

  4. The Effect of China’s Scramble for Resources and African Resource Nationalism on the Supply of Strategic Southern African Minerals: What Can the United States Do?

    Science.gov (United States)

    2010-01-01

    infrastructure remains the major impediment to sustaining and developing mining in South Africa, and it is a problem in the Democratic Republic of the Congo ...majority rule in 1994. The South African National Planning Commission, headed by former Finance Minister Trevor Manuel , pointed out in its “Vision for...Nationalism in the DRC In the Democratic Republic of the Congo (DRC), President Joseph Kabila leads a neo-patrimonial regime in a recovering failed

  5. Controls on large landslide distribution and implications for the geomorphic evolution of the southern interior Columbia River basin

    Science.gov (United States)

    Safran, E.B.; Anderson, S.W.; Mills-Novoa, M.; House, P.K.; Ely, L.

    2011-01-01

    Large landslides (>0.1 km2) are important agents of geomorphic change. While most common in rugged mountain ranges, large landslides can also be widespread in relatively low-relief (several 100 m) terrain, where their distribution has been relatively little studied. A fuller understanding of the role of large landslides in landscape evolution requires addressing this gap, since the distribution of large landslides may affect broad regions through interactions with channel processes, and since the dominant controls on landslide distribution might be expected to vary with tectonic setting. We documented >400 landslides between 0.1 and ~40 km2 across ~140,000 km2 of eastern Oregon, in the semiarid, southern interior Columbia River basin. The mapped landslides cluster in a NW-SE-trending band that is 50-100 km wide. Landslides predominantly occur where even modest local relief (~100 m) exists near key contacts between weak sedimentary or volcaniclastic rock and coherent cap rock. Fault density exerts no control on landslide distribution, while ~10% of mapped landslides cluster within 3-10 km of mapped fold axes. Landslide occurrence is curtailed to the NE by thick packages of coherent basalt and to the SW by limited local relief. Our results suggest that future mass movements will localize in areas stratigraphically preconditioned for landsliding by a geologic history of fluviolacustrine and volcaniclastic sedimentation and episodic capping by coherent lava flows. In such areas, episodic landsliding may persist for hundreds of thousands of years or more, producing valley wall slopes of ~7??-13?? and impacting local channels with an evolving array of mass movement styles. ?? 2011 Geological Society of America.

  6. Hydrologic Evaluation of Integrated Multi-satellite Retrivals for GPM over Nanliu River Basin in Southern China

    Science.gov (United States)

    Zhenqing, L.; Sheng, C.; Chaoying, H.

    2017-12-01

    The core satellite of Global Precipitation Measurement (GPM) mission was launched on 27 February2014 with two core sensors dual-frequency precipitation radar (DPR) and microwave imager (GMI). The algorithm of Integrated Multi-satellitE Retrievals for the Global Precipitation Measurement (GPM) mission (IMERG) blends the advantages of currently most popular satellite-based quantitative precipitation estimates (QPE) algorithms, i.e. TRMM Multi-satellite Precipitation Analysis (TMPA), Climate Prediction Center morphing technique (CMORPH) ADDIN EN.CITE ADDIN EN.CITE.DATA , Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS).Therefore, IMERG is deemed to be the state-of-art precipitation product with high spatio-temporal resolution of 0.1°/30min. The real-time and post real-time IMERG products are now available online at https://stormpps.gsfc.nasa.gov/storm. Early studies about assessment of IMERG with gauge observations or analysis products show that the current version GPM Day-1 product IMERG demonstrates promising performance over China [1], Europe [2], and United States [3]. However, few studies are found to study the IMERG' potentials of hydrologic utility.In this study, the real-time and final run post real-time IMERG products are hydrologically evaluated with gauge analysis product as reference over Nanliu River basin (Fig.1) in Southern China since March 2014 to February 2017 with Xinanjiang model. Statistics metrics Relative Bias (RB), Root-Mean-Squared Error (RMSE), Correlation Coefficient (CC), Probability Of Detection (POD), False Alarm Ratio (FAR), Critical Success Index (CSI), and Nash-Sutcliffe (NSCE) index will be used to compare the stream flow simulated with IMERG to the observed stream flow. This timely hydrologic evaluation is expected to offer insights into IMERG' potentials in hydrologic utility and thus provide useful feedback to the IMERG algorithm developers and

  7. Interannual sea level variability in the Pearl River Estuary and its response to El Niño-Southern Oscillation

    Science.gov (United States)

    Wang, Linlin; Li, Qiang; Mao, Xian-zhong; Bi, Hongsheng; Yin, Peng

    2018-03-01

    The South China coast, especially the Pearl River Estuary (PRE) region, is prosperous and densely populated, but vulnerable to sea level changes. Sea level anomalies (SLA) during 1954-2012 from tide gauge station data and regional SLAs during 1993-2012 from satellite altimetry are analyzed and compare to the El Niño-Southern Oscillation (ENSO). Results show that sea level declines during El Niño events and rises during La Niña. Sea level in the PRE responds to ENSO with 3-month lag. The ENSO can cause sea level in the PRE to fluctuate from -8.70 to 8.11 cm. Sea level cycles of 3 and 5 years are related to ENSO. The ENSO mechanism affecting sea level in the PRE was analyzed by identifying dominant regional and local forces. Weak/strong SLAs in most El Niño/La Niña events may be attributed to less/more seawater transport driven by anomalously weak/strong north winds and local anomalously high/low sea level pressure. Wind-driven coastal current is the predominant factor. It generated coastal seawater volume transport along a 160 km wide cross section to decrease by 21.07% in a typical El Niño period (January 2010) and increase by 44.03% in a typical La Niña period (January 2011) as compared to an ENSO neutral situation (January 2013). Results of sea level rise and its potential mechanism provide insight for disaster protection during extreme El Niño/La Niña events.

  8. PENGELOLAAN SUNGAI BERBASIS MASYARAKAT LOKAL DI DAERAH LERENG SELATAN GUNUNGAPI MERAPI (River Management Based on Local Community in the Southern Slope of Marapi Volcano

    Directory of Open Access Journals (Sweden)

    Darmakusuma Darmanto

    2013-07-01

    Full Text Available ABSTRAK Dalam kehidupan manusia, ternyata ada hubungan yang saling terkait antara manusia dengan sungai. Manusia memerlukan sungai untuk mendukung keperluan dan aktivitasnya, sebaliknya keberadaan sungai juga dapat dipengaruhi oleh aktivitas manusia. Dalam memanfaatkan dan memelihara sungai tidak terlepas dari pemanfaatan air di dalam sungai dan alur sungainya. Dalam memgelola sungai tidak terpisahkan antara pengelolaan air sungai dan alur sungainya. Hal tersebut juga tergantung dari karakteristik sungai dan kondisi sosial budaya masyarakat. Penelitian yang dilakukan di lereng selatan Gunungapi Merapi dengan cara survei di lapangan. Data dikumpulkan dengan observasi lapangan dan wawancara dengan masyarakat. Selanjutnya dikuti dengan analisis data secara deskriptif kualitatif. Sungai sungai besar di daerah penelitian telah dikelola oleh pemerintah, sedangkan masyarakat lebih berperan kepada pemanfaatan dan pemeliharaan sungai kecil. Berbagai penggunaan dilakukan terhadap sungai-sungai kecil, untuk keperluan rumah tangga, irigasi dan perikanan. Teknik pengambilan dan pemanfaatan air dilakukan dengan cara sederhana dengan beaya yang relatif murah, tetapi tetap mengedepankan azas kebersamaan dan keadilan. Pemeliharaan terhadap alur sungai terhadap kerusakkan lingkungan dilakukan berdasarkan atas kesadaran untuk keberlangsungan lingkungan dengan yang dilakukan secara perorangan dan berkelompok. Dalam pemeliharaan dikedepankan asas kegotongroyongan tanpa mengabaikan budaya masyarakat setempat. ABSTRACT In human life, there was a relationship between human activities with rivers. Humans need rivers to support their need and their activities; otherwise the existence of rivers can also be affected by human activities. The management of river cannot be separated from managing water in the river and its channels. It also depends on rivers characteristics as well as social and culture of the community. This research was conducted in the southern slopes of

  9. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African academics. ... search for an article by title, author/s or keywords,; and find other information ... Southern African Business Review; Project Work by Students for First ... The Basis of Distinction Between Qualitative and Quantitative Research in ...

  10. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African ... search for an article by title, author/s or keywords,; and find other information ... Southern African Business Review; Effect of Globalization on Sovereignty of States ... The Basis of Distinction Between Qualitative and Quantitative Research in ...

  11. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African ... search for an article by title, author/s or keywords,; and find other information sources ... Southern African Business Review; Conflicts in Africa: Meaning, Causes, ... The Basis of Distinction Between Qualitative and Quantitative Research in ...

  12. Impacts of Environmental Variables on a Phytoplankton Community: A Case Study of the Tributaries of a Subtropical River, Southern China

    Directory of Open Access Journals (Sweden)

    Zhaojiang Hou

    2018-02-01

    Full Text Available The phytoplankton community in the river is closely related to the location of the river and the impact of human activities. To summarize the patterns of phytoplankton community changes in rivers and to analyze the reasons for these patterns and differences, we sampled the three tributaries of the Dongjiang River at different latitudes in the dry and rainy season for three years. The results showed that the three rivers were mesotrophic, lightly eutrophic and moderately eutrophic respectively. From the south to the north, the water temperature and nutrition showed an increasing trend. In two different seasons, the differences in the water temperature and dissolved oxygen were clear. In the dry season, results of the multidimensional scaling (MDS analysis indicated that the phytoplankton community structures in the Li River and Qiuxiang River were similar. Regardless of the number of species, the cell abundance or the dominance index, Bacillariophyta were found to be dominant. Chlorophyta was dominant in the Danshui River. In the rainy season, Bacillariophyta, Bacillariophyta-Chlorophyta and Chlorophyta-Cyanophyta became the dominant types in the Li River, Qiuxiang River and Danshui River, respectively. These different patterns in phytoplankton community variation were affected by both the water quality and temperature.

  13. Possible zircon U-Pb evidence for Pan-African granulite-facies metamorphism in the Mozambique belt of southern Tanzania

    International Nuclear Information System (INIS)

    Coolen, J.J.M.M.M.

    1982-01-01

    Four zircon fractions of garnet-bearing two-pyroxene granulite, from the Furua granulite complex of southern Tanzania, plot very close to concordia. A discordia yields a lower intercept at 652 +- 10 Ma, an age slightly higher than the Rb-Sr whole-rock and mineral ages reported from the surrounding amphibolite-facies rocks. The U-Pb systematics indicate the presence of a very small amount of older (2-3 Ga) radiogenic lead. The zircon data may be interpreted as indicating an event of granulite-facies metamorphism during the Pan-African thermotectonic episode. This interpretation is at variance with current models postulating that the granulite complexes in the Mozambique belt are relicts of older, possibly Archaean events of metamorphism. (Auth.)

  14. Seasonal Variation and Ecosystem Dependence of Emission Factors for Selected Trace Gases and PM2.5 for Southern African Savanna Fires

    Science.gov (United States)

    Korontzi, S.; Ward, D. E.; Susott, R. A.; Yokelson, R. J.; Justice, C. O.; Hobbs, P. V.; Smithwick, E. A. H.; Hao, W. M.

    2003-01-01

    In this paper we present the first early dry season (early June-early August) emission factor measurements for carbon dioxide (CO2), carbon monoxide (CO), methane (Ca), nonmethane hydrocarbons (NMHC), and particulates with a diameter less than 2.5 microns (pM2.5) for southern African grassland and woodland fires. Seasonal emission factors for grassland fires correlate linearly with the proportion of green grass, used as a surrogate for the fuel moisture content, and are higher for products of incomplete combustion in the early part of the dry season compared with later in the dry season. Models of emission factors for NMHC and PM(sub 2.5) versus modified combustion efficiency (MCE) are statistically different in grassland compared with woodland ecosystems. We compare predictions based on the integration of emissions factors from this study, from the southern African Fire-Atmosphere Research Initiative 1992 (SAFARI-92), and from SAFARI-2000 with those based on the smaller set of ecosystem-specific emission factors to estimate the effects of using regional-average rather than ecosystem-specific emission factors. We also test the validity of using the SAFARI-92 models for emission factors versus MCE to predict the early dry season emission factors measured in this study. The comparison indicates that the largest discrepancies occur at the low end (0.907) and high end (0.972) of MCE values measured in this study. Finally, we combine our models of MCE versus proportion of green grass for grassland fires with emission factors versus MCE for selected oxygenated volatile organic compounds measured in the SAFARI-2000 campaign to derive the first seasonal emission factors for these compounds. The results of this study demonstrate that seasonal variations in savanna fire emissions are important and should be considered in modeling emissions at regional to continental scales.

  15. The African Crane Database (1978-2014): Records of three threatened crane species (Family: Gruidae) from southern and eastern Africa

    Science.gov (United States)

    Smith, Tanya; Page-Nicholson, Samantha; Gibbons, Bradley; Jones, M. Genevieve W.; van Niekerk, Mark; Botha, Bronwyn; Oliver, Kirsten; McCann, Kevin

    2016-01-01

    Abstract Background The International Crane Foundation (ICF) / Endangered Wildlife Trust’s (EWT) African Crane Conservation Programme has recorded 26 403 crane sightings in its database from 1978 to 2014. This sightings collection is currently ongoing and records are continuously added to the database by the EWT field staff, ICF/EWT Partnership staff, various partner organizations and private individuals. The dataset has two peak collection periods: 1994-1996 and 2008-2012. The dataset collection spans five African countries: Kenya, Rwanda, South Africa, Uganda and Zambia; 98% of the data were collected in South Africa. Georeferencing of the dataset was verified before publication of the data. The dataset contains data on three African crane species: Blue Crane Anthropoides paradiseus, Grey Crowned Crane Balearica regulorum and Wattled Crane Bugeranus carunculatus. The Blue and Wattled Cranes are classified by the IUCN Red List of Threatened Species as Vulnerable and the Grey Crowned Crane as Endangered. New information This is the single most comprehensive dataset published on African Crane species that adds new information about the distribution of these three threatened species. We hope this will further aid conservation authorities to monitor and protect these species. The dataset continues to grow and especially to expand in geographic coverage into new countries in Africa and new sites within countries. The dataset can be freely accessed through the Global Biodiversity Information Facility data portal. PMID:27956850

  16. Production of Landsat ETM+ reference imagery of burned areas within Southern African savannahs: comparison of methods and application to MODIS

    Science.gov (United States)

    A. M. S. Smith; N. A. Drake; M. J. Wooster; A. T. Hudak; Z. A. Holden; C. J. Gibbons

    2007-01-01

    Accurate production of regional burned area maps are necessary to reduce uncertainty in emission estimates from African savannah fires. Numerous methods have been developed that map burned and unburned surfaces. These methods are typically applied to coarse spatial resolution (1 km) data to produce regional estimates of the area burned, while higher spatial resolution...

  17. The impact of different sea-surface temperature prediction scenarios on Southern African seasonal climate forecast skill

    CSIR Research Space (South Africa)

    Landman, WA

    2009-12-01

    Full Text Available Retro-active forecasts produced at a 1-month lead-time by the ECHAM4.5 AGCM are statistically downscaled to South African district rainfall totals for the austral mid-summer season of December to February. The AGCM is forced with SST forecasts...

  18. Estimates of the topographic uplift of the Southern African Plateau from the African Superswell through petrologically-consistent thermo-chemical modelling of the geoid, SHF, Rayleigh and Love dispersion curves and MT data

    Science.gov (United States)

    Jones, Alan G.; Afonso, Juan Carlos; Fullea, Javier

    2015-04-01

    The deep mantle African Superswell is thought to cause up to 500 m of the uplift of the Southern African Plateau. We investigate this phenomenon through stochastic thermo-chemical inversion modelling of the geoid, surface heat flow, Rayleigh and Love dispersion curves and MT data, in a manner that is fully petrologically-consistent. We invert for a three layer crustal velocity, density and thermal structure, but assume the resistivity layering (based on prior inversion of the MT data alone). Inversions are performed using an improved Delayed Rejection and Adaptive Metropolis (DRAM) type Markov chain Monte Carlo (MCMC) algorithm. We demonstrate that a single layer lithosphere can fit most of the data, but not the MT responses. We further demonstrate that modelling the seismic data alone, without the constraint of requiring reasonable oxide chemistry or of fitting the geoid, permits wildly acceptable elevations and with very poorly defined lithosphere-asthenosphere boundary (LAB). We parameterise the lithosphere into three layers, and bound the permitted oxide chemistry of each layer consistent with known chemical layering. We find acceptable models, from 5 million tested in each case, that fit all responses and yield a posteriori elevation distributions centred on 900-950 m, suggesting dynamic support from the lower mantle of some 400 m.

  19. FOXO3 variants are beneficial for longevity in Southern Chinese living in the Red River Basin: A case-control study and meta-analysis

    OpenAIRE

    Sun, Liang; Hu, Caiyou; Zheng, Chenguang; Qian, Yu; Liang, Qinghua; Lv, Zeping; Huang, Zezhi; Qi, KeYan; Gong, Huan; Zhang, Zheng; Huang, Jin; Zhou, Qin; Yang, Ze

    2015-01-01

    Forkhead box class O (FOXO) transcription factors play a crucial role in longevity across species. Several polymorphisms in FOXO3 were previously reported to be associated with human longevity. However, only one Chinese replication study has been performed so far. To verify the role of FOXO3 in southern Chinese in the Red River Basin, a community-based case-control study was conducted, and seven polymorphisms were genotyped in 1336 participants, followed by a meta-analysis of eight case-contr...

  20. Uplift history of a transform continental margin revealed by the stratigraphic record: The case of the Agulhas transform margin along the Southern African Plateau

    Science.gov (United States)

    Baby, Guillaume; Guillocheau, François; Boulogne, Carl; Robin, Cécile; Dall'Asta, Massimo

    2018-04-01

    The south and southeast coast of southern Africa (from 28°S to 33°S) forms a high-elevated transform passive margin bounded to the east by the Agulhas-Falkland Fracture Zone (AFFZ). We analysed the stratigraphic record of the Outeniqua and Durban (Thekwini) Basins, located on the African side of the AFFZ, to determine the evolution of these margins from the rifting stage to present-day. The goal was to reconstruct the strike-slip evolution of the Agulhas Margin and the uplift of the inland high-elevation South African Plateau. The Agulhas transform passive margin results from four successive stages: Rifting stage, from Late Triassic to Early Cretaceous ( 200?-134 Ma), punctuated by three successive rifting episodes related to the Gondwana breakup; Wrench stage (134-131 Ma), evidenced by strike- and dip-slip deformations increasing toward the AFFZ; Active transform margin stage (131-92 Ma), during which the Falkland/Malvinas Plateau drifts away along the AFFZ, with an uplift of the northeastern part of the Outeniqua Basin progressively migrating toward the west; Thermal subsidence stage (92-0 Ma), marked by a major change in the configuration of the margin (onset of the shelf-break passive margin morphology). Two main periods of uplift were documented during the thermal subsidence stage of the Agulhas Margin: (1) a 92 Ma short-lived margin-scale uplift, followed by a second one at 76 Ma located along the Outeniqua Basin and; (2) a long-lasting uplift from 40 to 15 Ma limited to the Durban (Thekwini) Basin. This suggests that the South African Plateau is an old Upper Cretaceous relief (90-70 Ma) reactivated during Late Eocene to Early Miocene times (40-15 Ma).

  1. Magnetic signature of river sediments drained into the southern and eastern part of the South China Sea (Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan)

    Science.gov (United States)

    Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

    2017-01-01

    Magnetic properties of 22 river samples collected in the Malay Peninsula, Sumatra, Borneo, Luzon and Taiwan have been investigated in order to magnetically characterize the sediments drained and deposited into the South China Sea. The geological formations as well as the present climatic conditions are different from one region to another. Laboratory analyses include low-field magnetic susceptibility, anhysteretic (ARM) and isothermal (IRM) remanent magnetizations acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis cycles and low-temperature magnetic measurements. The magnetic properties indicate that the sediments are a mixture of hematite, magnetite and pyrrhotite in different proportions depending on the region. Combined with results previously reported for the three main Asian rivers (Pearl, Red and Mekong rivers), the new data indicate that, in general, hematite-rich sediments are delivered to the southern basin of the South China Sea while the northern basin is fed with magnetite and pyrrhotite-rich sediments. In addition to this general picture, some variability is observed at smaller geographic scales. Indeed, the magnetic assemblages are closely related to the geology of the various catchments while clay minerals, previously reported for the same samples, are more representative of the climatic conditions under which the parent rocks have evolved within each catchment. The magnetic fraction, now well characterized in the main river sediments drained into the South China Sea, can be used as a tracer for changes in precipitation on land and in oceanic water mass transport and exchange.

  2. Linking biochemical perturbations in tissues of the African catfish to the presence of polycyclic aromatic hydrocarbons in Ovia River, Niger Delta region

    International Nuclear Information System (INIS)

    Obinaju, Blessing E.; Graf, Carola; Halsall, Crispin; Martin, Francis L.

    2015-01-01

    Petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) are a pollution issue in the Niger Delta region due to oil industry activities. PAHs were measured in the water column of the Ovia River with concentrations ranging from 0.1 to 1055.6 ng L −1 . Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy detected alterations in tissues of the African catfish (Heterobranchus bidorsalis) from the region showed varying degrees of statistically significant (P < 0.0001, P < 0.001, P < 0.05) changes to absorption band areas and shifts in centroid positions of peaks. Alteration patterns were similar to those induced by benzo[a]pyrene in MCF-7 cells. These findings have potential health implications for resident local communities as H. bidorsalis constitutes a key nutritional source. The study provides supporting evidence for the sensitivity of infrared spectroscopy in environmental studies and supports their potential application in biomonitoring. - Highlights: • PAHs measured in the water column of the Ovia River (Nigeria). • ATR-FTIR spectroscopy detects alterations in tissues of the African catfish (Heterobranchus bidorsalis). • Spectral alteration similar to those induced by benzo[a]pyrene in MCF-7 cells. • Alterations in tissues of African catfish (H. bidorsalis) a function of exposure to waterborne PAHs. • Vibrational spectroscopy techniques detect minimal changes induced by environmental exposures. - Spatial and temporal analyses by biospectroscopy techniques of African catfish (Heterobranchus bidorsalis) tissues suggest that detected alterations can reflect fluctuating exposures to PAHs

  3. Sediment Budget Analysis and Hazard Assessment in the Peynin, a Small Alpine Catchment (Upper Guil River, Southern Alps, France)

    Science.gov (United States)

    Carlier, Benoit; Arnaud-Fassetta, Gilles; Fort, Monique; Bouccara, Fanny; Sourdot, Grégoire; Tassel, Adrien; Lissak, Candide; Betard, François; Cossart, Etienne; Madelin, Malika; Viel, Vincent; Charnay, Bérengère; Bletterie, Xavier

    2014-05-01

    The upper Guil catchment (Southern Alps) is prone to hydro-geomorphic hazards. Major hazards are related to catastrophic floods, with an amplification of their impacts due to strong hillslope-channel connectivity as observed in 1957 and 2000. In both cases, the rainfall intensity, aggravated by the pre-existing saturated soils, explained the instantaneous response of the fluvial system, such as destabilisation of slopes, high sediment discharge, and subsequent damages to exposed structures and settlements present in the floodplain and at confluence sites. The Peynin junction with the Guil River is one of these sites, where significant land-use change during the last decades in relation to the development of handicraft and tourism economy has increased debris flow threat to population. Here, we adopt a sediment budget analysis aimed at better understanding the functioning of this small subcatchment. This latter offers a combination of factors that favour torrential and gravitational activity. It receives abundant and intense rainfall during "Lombarde" events (moist air mass from Mediterranean Sea). Its elongated shape and small surface area (15 km²) together with asymmetric slopes (counter dip slope on the left bank) accelerate runoff on a short response time. In addition highly tectonised shaly schists supply a large volume of debris (mostly platy clasts and fine, micaceous sediment). The objectives of this study, carried out in the frame of SAMCO (ANR) project, are threefold: Identify the different sediment storages; Characterise the processes that put sediment into motion; Quantify volumes of sediment storages. We produced a geomorphic map using topographic surveys and aerial photos in order to locate the different sediment storage types and associated processes. This analysis was made with respect to geomorphic coupling and sediment flux activity. In terms of surface area, the dominant landforms in the valley were found to be mass wasting, talus slopes and

  4. Hydro-Geological Hazard Temporal Evolution during the last seven decades in the Solofrana River Basin—Southern Italy

    Science.gov (United States)

    Longobardi, Antonia; Diodato, Nazzareno; Mobilia, Mirka

    2017-04-01

    Extremes precipitation events are frequently associated to natural disasters falling within the broad spectrum of multiple damaging hydrological events (MDHEs), defined as the simultaneously triggering of different types of phenomena, such as landslides and floods. The power of the rainfall (duration, magnitude, intensity), named storm erosivity, is an important environmental indicator of multiple damaging hydrological phenomena. At the global scale, research interest is actually devoted to the investigation of non-stationary features of extreme events, and consequently of MDHEs, which appear to be increasing in frequency and severity. The Mediterranean basin appears among the most vulnerable regions with an expected increase in occurring damages of about 100% by the end of the century. A high concentration of high magnitude and short duration rainfall events are, in fact, responsible for the largest rainfall erosivity and erosivity density values within Europe. The aim of the reported work is to investigate the relationship between the temporal evolution of severe geomorphological events and combined precipitation indices as a tool to improve understanding the hydro-geological hazard at the catchment scale. The case study is the Solofrana river basin, Southern Italy, which has been seriously and consistently in time affected by natural disasters. Data for about 45 MDH events, spanning on a decadal scale 1951-2014, have been collected and analyzed for this purpose. A preliminary monthly scale analysis of event occurrences highlights a pronounced seasonal characterization of the phenomenon, as about 60% of the total number of reported events take place during the period from September to November. Following, a statistical analysis clearly indicates a significant increase in the frequency of occurrences of MDHEs during the last decades. Such an increase appears to be related to non-stationary features of an average catchment scale rainfall-runoff erosivity index

  5. Development and characterization of 10 microsatellite markers in the Cape horseshoe bat, Rhinolophus capensis (Chiroptera, Rhinolophidae) and cross-amplification in southern African Rhinolophus species.

    Science.gov (United States)

    Nesi, Nicolas; Jacobs, David S; Feldheim, Kevin; Bishop, Jacqueline M

    2015-09-26

    The Cape horseshoe bat, Rhinolophus capensis, is endemic to the Cape region of South Africa. Coalescent analysis of mitochondrial DNA sequence data suggests extensive historical gene flow between populations despite strong geographic variation of their echolocation call phenotype. Nevertheless the fine-scale genetic structure and evolutionary ecology of R. capensis remains poorly understood. Here we describe the development of 10 novel polymorphic microsatellite loci to investigate of the dispersal ecology of R. capensis and to facilitate taxonomic studies of Rhinolophus species in southern Africa. We report 10 microsatellite primer pairs that consistently amplify scorable and polymorphic loci across 12 African rhinolophid species. Initial analysis of two populations of R. capensis from South Africa revealed moderate to high levels of allelic variation with 4-14 alleles per locus and observed heterozygosities of 0.450-0.900. No evidence of linkage disequilibrium was observed and eight of the loci showed no departure from Hardy-Weinberg equilibrium. Cross-species utility of these markers revealed consistently amplifiable polymorphic loci in eleven additional rhinolophid species. The cross-amplification success of the microsatellites developed here provides a cost-effective set of population genetic marker for the study of rhinolophid evolutionary ecology and conservation in southern Africa.

  6. Developing a communication skills training program for pharmacists working in Southern African HIV/AIDS contexts: some notes on process and challenges.

    Science.gov (United States)

    Watermeyer, Jennifer

    2011-10-01

    In an attempt to understand why patients do not take medications, researchers are increasingly focusing on how communication processes influence adherence behaviors. Pharmacists have an important role to play in this regard. However, existing communication skills training (CST) programs for pharmacists are not necessarily sensitive to the needs of pharmacists working in specific contexts such as Southern Africa. In addition, CST programs are often poorly described in the literature, lack a theoretical background, and focus excessively on evaluation. This article describes the process of developing a CST program for pharmacists working in Southern African HIV/AIDS contexts, focusing on conceptualization and design. Some shortfalls in current approaches to CST are addressed. A number of sources were consulted during the development phase of the project, including interactional and focus group research, previously developed training models, analysis of currently available CST materials for pharmacists, and a literature review. These are discussed and some attention is also given to the challenges of implementing and evaluating the program. The project highlights the importance of providing CST that is disease- and context-specific, grounded in appropriate research and theoretical frameworks, and based on a rigorous process of development.

  7. Southern African guidelines on the safe use of pre-exposure prophylaxis in persons at risk of acquiring HIV-1 infection

    Directory of Open Access Journals (Sweden)

    Linda-Gail Bekker

    2016-03-01

    Full Text Available The Southern African HIV Clinicians Society published its first set of oral pre-exposure prophylaxis (PrEP guidelines in June 2012 for men who have sex with men (MSM who are at risk of HIV infection. With the flurry of data that has been generated in PrEP clinical research since the first guideline, it became evident that there was a need to revise and expand the PrEP guidelines with new evidence of safety and efficacy of PrEP in several populations, including MSM, transgender persons, heterosexual men and women, HIV-serodiscordant couples and people who inject drugs. This need is particularly relevant following the World Health Organization (WHO Consolidated Treatment Guidelines released in September 2015. These guidelines advise that PrEP is a highly effective, safe, biomedical option for HIV prevention that can be incorporated with other combination prevention strategies in Southern Africa, given the high prevalence of HIV in the region. PrEP should be tailored to populations at highest risk of HIV acquisition, whilst further data from studies in the region accrue to guide optimal deployment to realise the greatest impact regionally. PrEP may be used intermittently during periods of perceived HIV acquisition risk, rather than continually and lifelong, as is the case with antiretroviral treatment. Recognition and accurate measurement of potential risk in individuals and populations also warrants discussion, but are not extensively covered in these guidelines.

  8. Southern African guidelines on the safe use of pre-exposure prophylaxis in persons at risk of acquiring HIV-1 infection

    Science.gov (United States)

    Rebe, Kevin; Venter, Francois; Maartens, Gary; Moorhouse, Michelle; Conradie, Francesca; Wallis, Carole; Black, Vivian; Harley, Beth; Eakles, Robyn

    2016-01-01

    The Southern African HIV Clinicians Society published its first set of oral pre-exposure prophylaxis (PrEP) guidelines in June 2012 for men who have sex with men (MSM) who are at risk of HIV infection. With the flurry of data that has been generated in PrEP clinical research since the first guideline, it became evident that there was a need to revise and expand the PrEP guidelines with new evidence of safety and efficacy of PrEP in several populations, including MSM, transgender persons, heterosexual men and women, HIV-serodiscordant couples and people who inject drugs. This need is particularly relevant following the World Health Organization (WHO) Consolidated Treatment Guidelines released in September 2015. These guidelines advise that PrEP is a highly effective, safe, biomedical option for HIV prevention that can be incorporated with other combination prevention strategies in Southern Africa, given the high prevalence of HIV in the region. PrEP should be tailored to populations at highest risk of HIV acquisition, whilst further data from studies in the region accrue to guide optimal deployment to realise the greatest impact regionally. PrEP may be used intermittently during periods of perceived HIV acquisition risk, rather than continually and lifelong, as is the case with antiretroviral treatment. Recognition and accurate measurement of potential risk in individuals and populations also warrants discussion, but are not extensively covered in these guidelines. PMID:29568613

  9. Focus on CSIR research in pollution waste: South African national spatial biodiversity assessment 2004 (Technical report volume 2: river component)

    CSIR Research Space (South Africa)

    Roux, D

    2007-08-01

    Full Text Available the first ever systematic assessment of river biodiversity in South Africa. The approach and results should therefore be seen as the first attempt towards deriving a systematic and scientifically defensible method for identifying river heterogeneity...

  10. Linking biochemical perturbations in tissues of the African catfish to the presence of polycyclic aromatic hydrocarbons in Ovia River, Niger Delta region.

    Science.gov (United States)

    Obinaju, Blessing E; Graf, Carola; Halsall, Crispin; Martin, Francis L

    2015-06-01

    Petroleum hydrocarbons including polycyclic aromatic hydrocarbons (PAHs) are a pollution issue in the Niger Delta region due to oil industry activities. PAHs were measured in the water column of the Ovia River with concentrations ranging from 0.1 to 1055.6 ng L(-1). Attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy detected alterations in tissues of the African catfish (Heterobranchus bidorsalis) from the region showed varying degrees of statistically significant (Pinfrared spectroscopy in environmental studies and supports their potential application in biomonitoring. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Determinants of Persistence and Tolerance of Carnivores on Namibian Ranches: Implications for Conservation on Southern African Private Lands

    NARCIS (Netherlands)

    Lindsey, P.A.; Havemann, C.P.; Lines, R.M.; Palazy, L.; Price, A.E.; Retief, T.A.; Rhebergen, T.; Waal, van der C.

    2013-01-01

    Changing land use patterns in southern Africa have potential to dramatically alter the prospects for carnivore conservation. Understanding these influences is essential for conservation planning. We interviewed 250 ranchers in Namibia to assess human tolerance towards and the distribution of large

  12. Paleodrainages of the Eastern Sahara - The radar rivers revisited (SIR-A/B implications for a mid-tertiary Trans-African drainage system)

    Science.gov (United States)

    Mccauley, J. F.; Breed, C. S.; Schaber, G. G.; Mchugh, W. P.; Haynes, C. C.

    1986-01-01

    The images obtained by the Shuttle Imaging Radar (SIR)-A and -B systems over the southwestern Egypt and northwestern Sudan were coregistered with the Landsat images and the existing maps to aid in extrapolations of the buried paleodrainages ('radar rivers'), first discovered by SIR-A. Field observations explain the radar responses of three types of radar rivers, RR-1 (broad, aggraded valleys filled with alluvium), RR-2 (braided channels inset in the RR-1 valleys), and RR-3 (narrow, long, bedrock-incised channels). A generalized model of the radar rivers, based on field studies and regional geologic relations, shows inferred changes in river regimen since the large valleys were established during the later Paleogene-early Neogene. It is suggested that a former Trans-African master stream system may have flowed from headwaters in the Red Sea Hills southwestward across North Africa, discharging into the Atlantic at the Paleo-Niger delta, prior to the Neogene domal uplifts and building of volcanic edifices across the paths of these ancient watercourses.

  13. Spatio-Temporal Analysis of Vegetation Dynamics in Relation to Shifting Inundation and Fire Regimes: Disentangling Environmental Variability from Land Management Decisions in a Southern African Transboundary Watershed

    Directory of Open Access Journals (Sweden)

    Narcisa G. Pricope

    2015-07-01

    Full Text Available Increasing temperatures and wildfire incidence and decreasing precipitation and river runoff in southern Africa are predicted to have a variety of impacts on the ecology, structure, and function of semi-arid savannas, which provide innumerable livelihood resources for millions of people. This paper builds on previous research that documents change in inundation and fire regimes in the Chobe River Basin (CRB in Namibia and Botswana and proposes to demonstrate a methodology that can be applied to disentangle the effect of environmental variability from land management decisions on changing and ecologically sensitive savanna ecosystems in transboundary contexts. We characterized the temporal dynamics (1985–2010 of vegetation productivity for the CRB using proxies of vegetation productivity and examine the relative importance of shifts in flooding and fire patterns to vegetation dynamics and effects of the association of phases of the El Niño—Southern Oscillation (ENSO on vegetation greenness. Our results indicate that vegetation in these semi-arid environments is highly responsive to climatic fluctuations and the long-term trend is one of increased but heterogeneous vegetation cover. The increased cover and heterogeneity during the growing season is especially noted in communally-managed areas of Botswana where long-term fire suppression has been instituted, in contrast to communal areas in Namibia where heterogeneity in vegetation cover is mostly increasing primarily outside of the growing season and may correspond to mosaic early dry season burns. Observed patterns of increased vegetation productivity and heterogeneity may relate to more frequent and intense burning and higher spatial variability in surface water availability from both precipitation and regional inundation patterns, with implications for global environmental change and adaptation in subsistence-based communities.

  14. Mercury concentrations of fish in Southern Indian Lake and Issett Lake, Manitoba 1975-88: The effect of lake impoundment and Churchill River diversion

    International Nuclear Information System (INIS)

    Strange, N.E.; Bodaly, R.A.; Fudge, R.J.P.

    1991-01-01

    Southern Indian and Issett Lakes in northern Manitoba were flooded in 1976 as part of Manitoba Hydro's Churchill River diversion project. Fish were collected from 1975 to 1988 from five regional sites on the lakes to examine the effects of impoundment and river diversion on muscle mercury concentrations. Raw data for individual fish caught in 1987 and 1988 are presented, along with means and analyses calculated over the entire 1975-1988 study period. Mercury concentrations in whitefish, pike, and walleye increased significantly after impoundment. Whitefish mercury levels peaked in 1978 and have since declined to near pre-flooding levels. Northern pike and walleye mercury levels were much higher than for whitefish. Pike mercury concentrations showed no indication of declining after 12 years of impoundment, but walleye mercury levels at 2 of the 5 Southern Indian Lake sites declined from maximum recorded levels. Significant variability in fish mercury concentrations was noted both from year to year and among the sites. It is suggested that site-to-site variations are due to varying conditions in the reservoir which stimulate mercury methylation. Since there appears to be an ongoing long-term source of mercury and organic material from the eroding shorelines, pike and walleye mercury concentrations are expected to remain high for many years. 25 refs., 7 figs., 20 tabs

  15. El Niño-Southern Oscillation and water resources in the headwaters region of the Yellow River: links and potential for forecasting

    Directory of Open Access Journals (Sweden)

    A. Lü

    2011-04-01

    Full Text Available This research explores the rainfall-El Niño-Southern Oscillation (ENSO and runoff-ENSO relationships and examines the potential for water resource forecasting using these relationships. The Southern Oscillation Index (SOI, Niño1.2, Niño3, Niño4, and Niño3.4 were selected as ENSO indicators for cross-correlation analyses of precipitation and runoff. There was a significant correlation (95% confidence level between precipitation and ENSO indicators during three periods: January, March, and from September to November. In addition, monthly streamflow and monthly ENSO indictors were significantly correlated during three periods: from January to March, June, and from October to December (OND, with lag periods between one and twelve months. Because ENSO events can be accurately predicted one to two years in advance using physical modeling of the coupled ocean-atmosphere system, the lead time for forecasting runoff using ENSO indicators in the Headwaters Region of the Yellow River could extend from one to 36 months. Therefore, ENSO may have potential as a powerful forecasting tool for water resources in the headwater regions of Yellow River.

  16. Tropical systems from the southwest Indian Ocean making landfall over the Limpopo River Basin, southern Africa: a historical perspective

    CSIR Research Space (South Africa)

    Malherbe, J

    2011-03-01

    Full Text Available The study provides perspective on the contribution of landfalling tropical systems (cyclones, depressions, storms and lows) from the southwest Indian Ocean (SWIO) towards rainfall over the eastern interior of southern Africa, over the period 1948...

  17. Digitisation of the South African diatom collection

    CSIR Research Space (South Africa)

    Van

    2008-06-01

    Full Text Available stream_source_info van der Molen_2008.pdf.txt stream_content_type text/plain stream_size 1285 Content-Encoding UTF-8 stream_name van der Molen_2008.pdf.txt Content-Type text/plain; charset=UTF-8 Digitisation... of the South African Diatom Collection Johan van der Molen, CSIR Background ➲ Since 1950 ➲ Properly curated ➲ In dis-use since ~1990 ➲ Renewed interest since ~2004 ➲ Water bodies in Southern Africa, mostly rivers ➲ Supports taxonomic work and biological...

  18. Climate and southern Africa's water-energy-food nexus

    CSIR Research Space (South Africa)

    Conway, D

    2015-09-01

    Full Text Available be strengthened for this purpose: the Southern African Development Community, the Southern African Power Pool and trade of agricultural products amounting to significant transfers of embedded water....

  19. Impact of wastewater on fish health: a case study at the Neckar River (Southern Germany) using biomarkers in caged brown trout as assessment tools.

    Science.gov (United States)

    Vincze, Krisztina; Scheil, Volker; Kuch, Bertram; Köhler, Heinz R; Triebskorn, Rita

    2015-08-01

    The present work describes a field survey aiming at assessing the impact of a sewage treatment plant (STP) effluent on fish health by means of biomarkers. Indigenous fish were absent downstream of the STP. To elucidate the reason behind this, brown trout (Salmo trutta f. fario) were exposed in floating steel cages up- and downstream of a STP located at the Neckar River near Tübingen (Southern Germany), for 10 and 30 days. A combination of biomarker methods (histopathological investigations, analysis of the stress protein Hsp70, micronucleus test, B-esterase assays) offered the possibility to investigate endocrine, geno-, proteo- and neurotoxic effects in fish organs. Biological results were complemented with chemical analyses on 20 accumulative substances in fish tissue. Even after short-term exposure, biomarkers revealed clear evidence of water contamination at both Neckar River sites; however, physiological responses of caged brown trout were more severe downstream of the STP. According to this, similar bioaccumulation levels (low μg/kg range) of DDE and 12 polycyclic aromatic hydrocarbons (PAHs) were detected at both sampling sites, while up to fourfold higher concentrations of four PAHs, methyl-triclosan and two synthetic musks occurred in the tissues of downstream-exposed fish. The results obtained in this study suggest a constitutive background pollution at both sites investigated at the Neckar River and provided evidence for the additional negative impact of the STP Tübingen on water quality and the health condition of fish.

  20. Antimicrobial activity of southern African medicinal plants with dermatological relevance: From an ethnopharmacological screening approach, to combination studies and the isolation of a bioactive compound.

    Science.gov (United States)

    Mabona, Unathi; Viljoen, Alvaro; Shikanga, Emmanual; Marston, Andrew; Van Vuuren, Sandy

    2013-06-21

    Ethnobotanical reports on more than 100 southern African medicinal plants with dermatological relevance have been highlighted, yet there is still limited scientific data to support claims for their antimicrobial effectiveness against skin pathogens. Guided by ethnobotanical data, this paper explores the antimicrobial efficacies of southern African medicinal plants used to treat skin ailments. To investigate the antimicrobial properties of southern African medicinal plants against dermatologically relevant pathogens. The study also aimed at providing a scientific rationale for the traditional use of plant combinations to treat skin diseases and the isolation of the bio-active compound from the most active species, Aristea ecklonii (Iridaceae). Organic and aqueous extracts (132) were prepared from 47 plant species and screened for antimicrobial properties against dermatologically relevant pathogens using the micro-titre plate dilution method. Four different plant combinations were investigated for interactive properties and the sum of the fractional inhibitory concentration (ƩFIC) calculated. Isobolograms were used to further investigate the antimicrobial interactive properties of Pentanisia prunelloides combined with Elephantorrhiza elephantina at varied ratios. A bioactivity-guided fractionation process was adopted to fractionate the organic leaf extract of Aristea ecklonii. Plants demonstrating notable broad-spectrum activities (MIC values ≤1.00mg/ml) against the tested pathogens included extracts from Aristea ecklonii, Chenopodium ambrosioides, Diospyros mespiliformis, Elephantorrhiza elephantina, Eucalyptus camaldulensis, Gunnera perpensa, Harpephyllum caffrum, Hypericum perforatum, Melianthus comosus, Terminalia sericea and Warburgia salutaris. The organic extract of Elephantorrhiza elephantina, a plant reportedly used to treat acne vulgaris, demonstrated noteworthy antimicrobial activity (MIC value of 0.05mg/ml) against Propionibacterium acnes. Similarly

  1. The role of pioneers as indicators of biogeographic range expansion caused by global change in southern African coastal waters

    Science.gov (United States)

    Whitfield, Alan K.; James, Nicola C.; Lamberth, Stephen J.; Adams, Janine B.; Perissinotto, Renzo; Rajkaran, Anusha; Bornman, Thomas G.

    2016-04-01

    The South African coastline is just over 3000 km in length yet it covers three major biogeographic regions, namely subtropical, warm temperate and cool temperate. In this review we examine published information to assess the possible role of climate change in driving distributional changes of a wide variety of organisms around the subcontinent. In particular we focus on harmful algal blooms, seaweeds, eelgrass, mangroves, salt marsh plants, foraminiferans, stromatolites, corals, squid, zooplankton, zoobenthos, fish, birds, crocodiles and hippopotamus, but also refer to biota such as pathogens, coralline algae, jellyfish and otters. The role of pioneers or propagules as indicators of an incipient range expansion are discussed, with mangroves, zoobenthos, fishes and birds providing the best examples of actual and imminent distributional changes. The contraction of the warm temperate biogeographic region, arising from the intrusion of cool upwelled waters along the Western Cape shores, and increasingly warm Agulhas Current waters penetrating along the eastern parts of the subcontinent, are highlighted. The above features provide an ideal setting for the monitoring of biotic drivers and responses to global climate change over different spatial and temporal scales, and have direct relevance to similar studies being conducted elsewhere in the world. We conclude that, although this review focuses mainly on the impact of global climate change on South African coastal biodiversity, other anthropogenic drivers of change such as introduced alien invasive species may act synergistically with climate change, thereby compounding both short and long-term changes in the distribution and abundance of indigenous species.

  2. Contribution to the caryological study of the African grass Aristida rhiniochloa Hochst., based on specimens from the Southern Hemisphere

    Directory of Open Access Journals (Sweden)

    Pierre Bourreil

    1972-11-01

    Full Text Available The chromosome number established for Aristida rhiniochloa Hochst. by the study of material from three localities in the Southern Hemisphere confirms the results obtained on material from North Africa. The haploid complement (n = 11 and the diploid number (2n = 22 of this species conform to the basic number x = 11 typical for the Aristideae. It is shown that the caryotype of this species is sub-symmetrical. Preliminary studies o f material from two localities show that the meiotic behaviour conforms to that found in the diploid species with n bivalents.

  3. Ethical quandaries in spiritual healing and herbal medicine: A critical analysis of the morality of traditional medicine advertising in southern African urban societies

    Science.gov (United States)

    Munyaradzi, Mawere

    2011-01-01

    This paper critically examines the morality of advertising by practitioners in spiritual healing and herbal medicine heretofore referred to as traditional medicine, in southern African urban societies. While the subject of traditional medicine has been heavily contested in medical studies in the last few decades, the monumental studies on the subject have emphasised the place of traditional medicine in basic health services. Insignificant attention has been devoted to examine the ethical problems associated with traditional medicine advertising. Critical look at the worthiness of some advertising strategies used by practitioners in traditional medicine in launching their products and services on market thus has been largely ignored. Yet, though advertising is key to helping traditional medicine practitioners’ products and services known by prospective customers, this research registers a number of morally negative effects that seem to outweigh the merits that the activity brings to prospective customers. The paper adopts southern African urban societies, and in particular Mozambique, South Africa and Zimbabwe as particular references. The choice of the trio is not accidental, but based on the fact that these countries have in the last few decades been flooded with traditional medicine practitioners/traditional healers from within the continent and from abroad. Most of these practitioners use immoral advertising strategies in communicating to the public the products and services they offer. It is against this background that this paper examines the morality of advertising strategies deployed by practitioners in launching their products and services. To examine the moral worthiness of the advertising strategies used by traditional medical practitioners, I used qualitative analysis of street adverts as well as electronic and print media. From the results obtained through thematic content analysis, the paper concludes that most of the practitioners in traditional

  4. Ethical quandaries in spiritual healing and herbal medicine: a critical analysis of the morality of traditional medicine advertising in southern African urban societies.

    Science.gov (United States)

    Munyaradzi, Mawere

    2011-01-01

    This paper critically examines the morality of advertising by practitioners in spiritual healing and herbal medicine heretofore referred to as traditional medicine, in southern African urban societies. While the subject of traditional medicine has been heavily contested in medical studies in the last few decades, the monumental studies on the subject have emphasised the place of traditional medicine in basic health services. Insignificant attention has been devoted to examine the ethical problems associated with traditional medicine advertising. Critical look at the worthiness of some advertising strategies used by practitioners in traditional medicine in launching their products and services on market thus has been largely ignored. Yet, though advertising is key to helping traditional medicine practitioners' products and services known by prospective customers, this research registers a number of morally negative effects that seem to outweigh the merits that the activity brings to prospective customers. The paper adopts southern African urban societies, and in particular Mozambique, South Africa and Zimbabwe as particular references. The choice of the trio is not accidental, but based on the fact that these countries have in the last few decades been flooded with traditional medicine practitioners/traditional healers from within the continent and from abroad. Most of these practitioners use immoral advertising strategies in communicating to the public the products and services they offer. It is against this background that this paper examines the morality of advertising strategies deployed by practitioners in launching their products and services. To examine the moral worthiness of the advertising strategies used by traditional medical practitioners, I used qualitative analysis of street adverts as well as electronic and print media. From the results obtained through thematic content analysis, the paper concludes that most of the practitioners in traditional

  5. Energy Trade in Southern Africa

    International Nuclear Information System (INIS)

    Holland, W F.

    1996-01-01

    This document deals with possible energy growth in Southern African countries. This region possesses substantial energy resources (including fossil fuels), but because of political instability, government intervention, financial paralysis and lack of adequate transportation infrastructure, this region faces problems in satisfying energy needs. Two key international actions, namely the South African Development Community (SADC) Energy Protocol and the Southern African Power Pool (SAPP) are expected to enhance energy trade and promote economic development. (TEC)

  6. High incidence of the median artery of the forearm in a sample of recent southern African cadavers.

    Science.gov (United States)

    Henneberg, M; George, B J

    1992-01-01

    Observations of the presence of the median artery, providing substantial blood supply to the hand, were conducted on 96 dissected forearms of 15 adult African females and 49 adult males. The artery has a much higher incidence (27.1%) than previously reported by any author. There is no significant difference in its occurrence between sexes, nor between right and left limbs. The artery seems to occur more often bilaterally than unilaterally. The presence of the artery is not related to age. From a theoretical standpoint it is difficult to accept that a structure present in more than 1 in 4 of individuals should be considered an 'anomaly' or a 'variant'. A different approach to description of normal human anatomy is therefore necessary--that of presenting alternative anatomical patterns of equal standing rather than a single 'normal' pattern. Images Fig. 1 Fig. 2 Fig. 3 PMID:1452474

  7. The African oil industry

    International Nuclear Information System (INIS)

    Ford, Mark; Griffiths, Thalia

    1999-10-01

    Contains Executive Summary and Chapters on: Adding value to African hydrocarbons in a global energy market; North Africa; East Africa; West Africa; Central Africa; Southern Africa; Strategies for Africa; Outlook. (Author)

  8. African Journals Online: Zimbabwe

    African Journals Online (AJOL)

    Items 1 - 12 of 12 ... SAFERE: Southern African Feminist Review. SAFERE provides women with a writing platform which is feminist in content and ... The Zimbabwe Journal of Educational Research comprised of four sections: Scholarly articles ...

  9. Role of the Angola Low in modulating southern African austral summer rainfall and relationships with synoptic and interannual modes of variability

    Science.gov (United States)

    Crétat, Julien; Pohl, Benjamin; Dieppois, Bastien

    2017-04-01

    The Angola Low has been suggested in many previous studies to be an important regional feature governing southern African rainfall variability during austral summer, which is, in particular, expressed through modulations of El Niño Southern Oscillation (ENSO) impacts on rainfall at the interannual timescale. Here, we analyse a variety of state-of-the-art reanalyses (NCEP2, ERA-Interim and MERRA2) and rainfall data (in situ rain-gauges and satellite-derived products) for: i) identifying the recurrent regimes of the Angola Low (position and intensity) at the daily timescale; ii) diagnosing how they modulate the spatio-temporal variability of austral summer rainfall; and iii) examining their relationships with synoptic convective regimes and ENSO, both at the interannual timescale. The recurrent regimes of the Angola Low are identified over the 1980-2015 period by applying a cluster analysis to daily 700-hPa wind vorticity anomalies over the Angola sector from November to March. The exact number and morphological properties of vorticity regimes vary significantly among the reanalyses, in particular when using the lowest spatial resolution reanalysis (i.e., NCEP2) that leads to detect less diversity, smoothest patterns and weakest intensity across the recurrent regimes. Despite such uncertainties, the regimes describing active Angola Low are quite robust among the reanalyses. Three preferential locations (locked over eastern Angola, shifted few degrees eastward or south-westward), which significantly impact on the rainfall spatial distribution over tropical and subtropical southern Africa, are identified. Independently from its location, Angola Low favours moisture advection from the southwest Indian Ocean and reduces moisture export towards the southeast Atlantic, hence contributing to increase moisture convergence over the subcontinent. Lead/lag correlations with synoptic convective regimes suggest that Angola Low may be a local precursor of tropical

  10. Incorporating trnH-psbA to the core DNA barcodes improves significantly species discrimination within southern African Combretaceae

    Directory of Open Access Journals (Sweden)

    Jephris Gere

    2013-12-01

    Full Text Available Recent studies indicate that the discriminatory power of the core DNA barcodes (rbcLa + matK for land plants may have been overestimated since their performance have been tested only on few closely related species. In this study we focused mainly on how the addition of complementary barcodes (nrITS and trnH-psbA to the core barcodes will affect the performance of the core barcodes in discriminating closely related species from family to section levels. In general, we found that the core barcodes performed poorly compared to the various combinations tested. Using multiple criteria, we finally advocated for the use of the core + trnH-psbA as potential DNA barcode for the family Combretaceae at least in southern Africa. Our results also indicate that the success of DNA barcoding in discriminating closely related species may be related to evolutionary and possibly the biogeographic histories of the taxonomic group tested.

  11. Determinants of persistence and tolerance of carnivores on Namibian ranches: implications for conservation on Southern African private lands.

    Directory of Open Access Journals (Sweden)

    Peter Andrew Lindsey

    Full Text Available Changing land use patterns in southern Africa have potential to dramatically alter the prospects for carnivore conservation. Understanding these influences is essential for conservation planning. We interviewed 250 ranchers in Namibia to assess human tolerance towards and the distribution of large carnivores. Cheetahs (Acinonyx jubatus, leopards (Panthera pardus and brown hyaenas (Hyaena brunnea were widely distributed on Namibian farmlands, spotted hyaenas (Crocuta crocuta had a narrower distribution, and wild dogs (Lycaon pictus and lions (Panthera leo are largely limited to areas near source populations. Farmers were most tolerant of leopards and least tolerant of lions, wild dogs and spotted hyaenas. Several factors relating to land use correlated consistently with carnivore-presence and landowner tolerance. Carnivores were more commonly present and/or tolerated where; wildlife diversity and biomass were higher; income from wildlife was higher; income from livestock was lower; livestock biomass was lower; in conservancies; game fencing was absent; and financial losses from livestock depredation were lower. Efforts to create conditions whereby the costs associated with carnivores are lowest, and which confer financial value to them are likely to be the most effective means of promoting carnivore conservation. Such conditions are achieved where land owners pool land to create conservancies where livestock are replaced with wildlife (or where livestock husbandry is improved and where wildlife generates a significant proportion of ranch income. Additional measures, such as promoting improved livestock husbandry and educational outreach efforts may also help achieve coexistence with carnivores. Our findings provide insights into conditions more conducive to the persistence of and tolerance towards large carnivores might be increased on private (and even communal lands in Namibia, elsewhere in southern and East Africa and other parts of the world

  12. Shear Wave Velocity Structure of Southern African Crust: Evidence for Compositional Heterogeneity within Archaean and Proterozoic Terrains

    Energy Technology Data Exchange (ETDEWEB)

    Kgaswane, E M; Nyblade, A A; Julia, J; Dirks, P H H M; Durrheim, R J; Pasyanos, M E

    2008-11-11

    Crustal structure in southern Africa has been investigated by jointly inverting receiver functions and Rayleigh wave group velocities for 89 broadband seismic stations spanning much of the Precambrian shield of southern Africa. 1-D shear wave velocity profiles obtained from the inversion yield Moho depths that are similar to those reported in previous studies and show considerable variability in the shear wave velocity structure of the lower part of the crust between some terrains. For many of the Archaean and Proterozoic terrains in the shield, S velocities reach 4.0 km/s or higher over a substantial part of the lower crust. However, for most of the Kimberley terrain and adjacent parts of the Kheis Province and Witwatersrand terrain, as well as for the western part of the Tokwe terrain, mean shear wave velocities of {le} 3.9 km/s characterize the lower part of the crust along with slightly ({approx}5 km) thinner crust. These findings indicate that the lower crust across much of the shield has a predominantly mafic composition, except for the southwest portion of the Kaapvaal Craton and western portion of the Zimbabwe Craton, where the lower crust is intermediate-to-felsic in composition. The parts of the Kaapvaal Craton underlain by intermediate-to-felsic lower crust coincide with regions where Ventersdorp rocks have been preserved, and thus we suggest that the intermediate-to-felsic composition of the lower crust and the shallower Moho may have resulted from crustal melting during the Ventersdorp tectonomagmatic event at c. 2.7 Ga and concomitant crustal thinning caused by rifting.

  13. The Permo-Triassic uranium deposits of Southern Africa within the African-South American Gondwana framework

    International Nuclear Information System (INIS)

    Toens, P.D.; Le Roux, J.P.

    1981-01-01

    The discovery of uranium in the Permo-Triassic Gondwana in South America and Africa has served to highlight the intercontinental correlations. The purpose here is to examine the uranium deposits of Southern Africa in the light of the similarities that exist between the various Gondwana formations of the two continents. This hopefully will assist in gaining some understanding of the genesis of the uranium mineralization and the sedimentary environment in which such deposits are likely to occur. Between the Upper Carboniferous and the Jurassic a tectono-sedimentary terrain existed within Gondwanaland in which broadly similar conditions prevailed over large areas, thus producing numerous partly disconnected basins practically identical in character. The basal formations are composed of glacial tillite followed by a succession of sandstone and shale which attains a thickness of up to 12,000 m. Sedimentological studies confirm that major source areas composed largely of granitic and metamorphic rocks existed to the north and south of central South America and Southern Africa, as also in the divides between the basins. Uranium mineralization occurs sporadically throughout the succession and is usually restricted to palaeoriver channels containing carbon trash. There has been little subsequent enrichment and the Colorado model does not apply. With a few exceptions, the deposits tend to have a low overall uranium tenor and individual deposits are usually not very extensive in size. Collectively, however, they may eventually assume some importance. Uraniferous coals have been recorded from a number of localities and it is suggested that the significance of these deposits has as yet not been fully appreciated or investigated. (author)

  14. Forced sexual experiences as risk factor for self-reported HIV infection among southern African lesbian and bisexual women.

    Directory of Open Access Journals (Sweden)

    Theo G M Sandfort

    Full Text Available Even though women who have sex with women are usually understood to be at no or very low risk for HIV infection, we explored whether lesbian and bisexual women in a geographical area with high HIV prevalence (Southern Africa get tested for HIV and whether, among those women who get tested, there are women who live with HIV/AIDS. The study was conducted in collaboration with community-based organizations in Botswana, Namibia, South Africa and Zimbabwe. Data were collected via written surveys of women who in the preceding year had had sex with a woman (18 years and older; N = 591. Most participating women identified as lesbian and black. Almost half of the women (47.2% reported ever having had consensual heterosexual sex. Engagement in transactional sex (lifetime was reported by 18.6% of all women. Forced sex by men or women was reported by 31.1% of all women. A large proportion of the women reported to ever have been tested for HIV (78.3%; number of lifetime female and male partners was independently associated with having been tested; women who had engaged in transactional sex with women only or with women and men were less likely to have been tested. Self-reported HIV prevalence among tested women who knew their serostatus was 9.6%. Besides age, the sole independent predictor of a positive serostatus was having experienced forced sex by men, by women, or by both men and women. Study findings indicate that despite the image of invulnerability, HIV/AIDS is a reality for lesbian and bisexual women in Southern Africa. Surprisingly, it is not sex with men per se, but rather forced sex that is the important risk factor for self-reported HIV infection among the participating women. HIV/AIDS policy should also address the needs of lesbian, bisexual and other women who have sex with women.

  15. Correlates of male circumcision in Eastern and Southern African countries: establishing a baseline prior to VMMC Scale-up.

    Directory of Open Access Journals (Sweden)

    Khai Hoan Tram

    Full Text Available BACKGROUND: Despite the importance of male circumcision (MC prevalence to HIV prevention efforts in Eastern and Southern Africa, there has been no systematic analysis on the correlates of male circumcision. This analysis identifies correlates of MC in 12 countries in the region with available data. METHODS: Data from the male questionnaire of DHS surveys collected between 2006-2011 in Ethiopia, Kenya, Lesotho, Malawi, Mozambique, Namibia, Rwanda, Swaziland, Tanzania, Uganda, Zambia, and Zimbabwe were analyzed. The dependent variable was self-reported male circumcision status. Independent variables included age, education, wealth quintile, place of residence, ethnicity, religion and region. Bivariate and multivariate analyses were conducted separately for each country. RESULTS: MC prevalence ranged from 8.2 percent in Swaziland to 92.2 percent in Ethiopia. Bivariate analyses showed a consistent positive association between age (being older and male circumcision. Education, wealth quintile, and place of residence were either not significantly related or differed in the direction of the relationship by country. Multivariate logistic regression showed three variables consistently associated with MC status: age (being older, religion (being Muslim and ethnicity. DISCUSSION: These data were collected prior to the scale-up of voluntary medical male circumcision (VMMC programs in 11 of the 12 countries. As the VMMC scale-up intensifies in countries across Eastern and Southern Africa, the correlates of VMMC are likely to change, with (younger age and education emerging as key correlates of VMMC performed in medical settings. The centuries-long tradition among Muslims to circumcise should continue to favor MC among this group. Non-circumcising ethnicities may become more open to MC if promoted as a health practice for decreasing HIV risk.

  16. Rapid assessment and mapping of tree cover in southern African savanna woodlands using a new iPhone App and Landsat 8 imagery

    Science.gov (United States)

    Fuller, D. O.

    2016-12-01

    Tree cover is a key parameter in climate modeling. It strongly influences CO2 exchanges between the land surface and atmosphere and surface energy balance. We measured percent woody canopy cover (PWCC) in the savanna woodlands of eastern Zambia over a 10-day period in May 2016 using a new iPhone App (CanopyApp) and related these field measurements to Landsat 8 (L8) Band 4 (red) imagery acquired approximately the same time. We then used parameters from the band 4 digital numbers (DNs)-PWCC linear regression to derive a new map of PWCC for the entire L8 scene. Consistent with theory and previous empirical studies, we found that the relationship between L8 band 4 DNs- PWCC was negative and linear (r2 = 0.61, p reflectance was weaker (r2 = 0.46, p shadowing effects and other spatial inhomogeneities from variable soil and background reflectance. Our PWCC map agreed qualitatively with similar percent tree-cover maps based on Landsat level 1 products and past field studies in the area conducted using a hemispherical lens. Our results also compared favorably with other remote sensing studies that have used complex multivariate approaches to estimate tree cover, which suggests that use of a single L8 band 4 is sufficient to estimate PWCC when spectral contrast exists between the grass, soil and tree layers during the austral fall period in southern African savannas.

  17. Water quality assessment in the "German River of the years 2014/2015": how a case study on the impact of a storm water sedimentation basin displayed impairment of fish health in the Argen River (Southern Germany).

    Science.gov (United States)

    Thellmann, Paul; Kuch, Bertram; Wurm, Karl; Köhler, Heinz-R; Triebskorn, Rita

    2017-01-01

    The present work investigates the impact of discharges from a storm water sedimentation basin (SSB) receiving runoff from a connected motorway in southern Germany. The study lasted for almost two years and was aimed at assessing the impact of the SSB on the fauna of the Argen River, which is a tributary of Lake Constance. Two sampling sites were examined up- and downstream of the SSB effluent. A combination of different diagnostic methods (fish embryo test with the zebrafish, histopathology, micronucleus test) was applied to investigate health impairment and genotoxic effects in indigenous fish as well as embryotoxic potentials in surface water and sediment samples of the Argen River, respectively, in samples of the SSB effluent. In addition, sediment samples from the Argen River and tissues of indigenous fish were used for chemical analyses of 33 frequently occurring pollutants by means of gas chromatography. Furthermore, the integrity of the macrozoobenthos community and the fish population were examined at both investigated sampling sites. The chemical analyses revealed a toxic burden with trace substances (originating from traffic and waste water) in fish and sediments from both sampling sites. Fish embryo tests with native sediment and surface water samples resulted in various embryotoxic effects in exposed zebrafish embryos (Fig. 1). In addition, the health condition of the investigated fish species (e.g., severe alterations in the liver and kidney) provided clear evidence of water contamination at both Argen River sites (Fig. 2). At distinct points in time, some parameters (fish development, kidney and liver histopathology) indicated stronger effects at the sampling site downstream of the SSB effluent than at the upstream site. Our results clearly showed that the SSB cannot be assigned as the main source of pollutants that are released into the investigated Argen River section. Moreover, we showed that there is moderate background pollution with substances

  18. Parameterization of a complex landscape for a sediment routing model of the Le Sueur River, southern Minnesota

    Science.gov (United States)

    Belmont, P.; Viparelli, E.; Parker, G.; Lauer, W.; Jennings, C.; Gran, K.; Wilcock, P.; Melesse, A.

    2008-12-01

    Modeling sediment fluxes and pathways in complex landscapes is limited by our inability to accurately measure and integrate heterogeneous, spatially distributed sources into a single coherent, predictive geomorphic transport law. In this study, we partition the complex landscape of the Le Sueur River watershed into five distributed primary source types, bluffs (including strath terrace caps), ravines, streambanks, tributaries, and flat,agriculture-dominated uplands. The sediment contribution of each source is quantified independently and parameterized for use in a sand and mud routing model. Rigorous modeling of the evolution of this landscape and sediment flux from each source type requires consideration of substrate characteristics, heterogeneity, and spatial connectivity. The subsurface architecture of the Le Sueur drainage basin is defined by a layer cake sequence of fine-grained tills, interbedded with fluvioglacial sands. Nearly instantaneous baselevel fall of 65 m occurred at 11.5 ka, as a result of the catastrophic draining of glacial Lake Agassiz through the Minnesota River, to which the Le Sueur is a tributary. The major knickpoint that was generated from that event has propagated 40 km into the Le Sueur network, initiating an incised river valley with tall, retreating bluffs and actively incising ravines. Loading estimates constrained by river gaging records that bound the knick zone indicate that bluffs connected to the river are retreating at an average rate of less than 2 cm per year and ravines are incising at an average rate of less than 0.8 mm per year, consistent with the Holocene average incision rate on the main stem of the river of less than 0.6 mm per year. Ongoing work with cosmogenic nuclide sediment tracers, ground-based LiDAR, historic aerial photos, and field mapping will be combined to represent the diversity of erosional environments and processes in a single coherent routing model.

  19. FOXO3 variants are beneficial for longevity in Southern Chinese living in the Red River Basin: A case-control study and meta-analysis.

    Science.gov (United States)

    Sun, Liang; Hu, Caiyou; Zheng, Chenguang; Qian, Yu; Liang, Qinghua; Lv, Zeping; Huang, Zezhi; Qi, KeYan; Gong, Huan; Zhang, Zheng; Huang, Jin; Zhou, Qin; Yang, Ze

    2015-04-27

    Forkhead box class O (FOXO) transcription factors play a crucial role in longevity across species. Several polymorphisms in FOXO3 were previously reported to be associated with human longevity. However, only one Chinese replication study has been performed so far. To verify the role of FOXO3 in southern Chinese in the Red River Basin, a community-based case-control study was conducted, and seven polymorphisms were genotyped in 1336 participants, followed by a meta-analysis of eight case-control studies that included 5327 longevity cases and 4608 controls. In our case-control study, we found rs2802288*A and rs2802292*G were beneficial to longevity after Bonferroni correction (pallele = 0.005, OR = 1.266; pallele = 0.026, OR = 1.207). In addition, in the longevity group, carriers with rs2802288*A and rs2802292*G presented reduced HbA1c (p = 0.001), and homozygotes of rs2802292*GG presented improved HOMA-IR (p = 0.014). The meta-analysis further revealed the overall contribution of rs2802288*A and rs2802292*G to longevity. However, our stratified analysis revealed that rs2802292*G might act more strongly in Asians than Europeans, for enhancement of longevity. In conclusion, our study provides convincing evidence for a significant association between the rs2802288*A and rs2802292*G gene variants in FOXO3 and human longevity, and adds the Southern Chinese in the Red River Basin to the growing number of human replication populations.

  20. Innovative solutions for intractable water problems in the face of climate change in southern and East African sub regions

    Science.gov (United States)

    Mapani, Benjamin; Makurira, Hodson; Magole, Lapologang; Meck, Maideyi; Mkandawire, Theresa; Mul, Marloes; Ngongondo, Cosmo

    2018-06-01

    This issue has a total of thirty-two (32) papers; and covers the IWRM sub themes of Hydrology, Land and People, Water Resources Management, Water and Environment and Wastewater and Sanitation. Water issues have become more and more complex as the supply side is affected by issues of quantity, availability and vulnerability due to natural factors such as climate change and urbanization. These challenges call for new management strategies and governance styles. Access to clean freshwater is a basic requirement for enhanced quality of life and development by all. However, this access has three main components that must be met adequately as this issue illustrates. These components are firstly, the quantity of water available; secondly, the quality and thirdly supply and appropriate delivery of this precious resource to domestic, commercial and industrial users. The demand side has also become more challenging, especially in urban areas as more and more people move from the rural areas to the cities. It has become a daily challenge in many African cities to supply water to these new urban dwellers and more so in unplanned settlements. These issues require a way and manner of delivering solutions and new innovative ideas. The topics in this issue vary from climate variability and how we are to improve our management strategies to mitigation, through to vulnerability of water resources and how to strengthen governance issues that plague some institutions in our region.

  1. Large Scale Screening of Southern African Plant Extracts for the Green Synthesis of Gold Nanoparticles Using Microtitre-Plate Method

    Directory of Open Access Journals (Sweden)

    Abdulrahman M. Elbagory

    2016-11-01

    Full Text Available The preparation of gold nanoparticles (AuNPs involves a variety of chemical and physical methods. These methods use toxic and environmentally harmful chemicals. Consequently, the synthesis of AuNPs using green chemistry has been under investigation to develop eco-friendly nanoparticles. One approach to achieve this is the use of plant-derived phytochemicals that are capable of reducing gold ions to produce AuNPs. The aim of this study was to implement a facile microtitre-plate method to screen a large number of aqueous plant extracts to determine the optimum concentration (OC for the bio-synthesis of the AuNPs. Several AuNPs of different sizes and shapes were successfully synthesized and characterized from 17 South African plants. The characterization was done using Ultra Violet-Visible Spectroscopy, Dynamic Light Scattering, High Resolution Transmission Electron Microscopy and Energy-Dispersive X-ray Spectroscopy. We also studied the effects of temperature on the synthesis of the AuNPs and showed that changes in temperatures affect the size and dispersity of the generated AuNPs. We also evaluated the stability of the synthesized AuNPs and showed that some of them are stable in biological buffer solutions.

  2. Pan-African tectonic evolution in central and southern Cameroon: transpression and transtension during sinistral shear movements

    Science.gov (United States)

    Ngako, V.; Affaton, P.; Nnange, J. M.; Njanko, Th.

    2003-04-01

    Kinematic analysis of the central Cameroon shear zone (CCSZ) and its Sanaga fault relay, indicate early sinistral shear movement (phase D 2) that was later followed by a dextral shear movement (phase D 3) during the Pan-African orogeny. The correlation of tectonic events among the CCSZs, thrusting of the Yaounde Group and the deformation in the Lom Group indicate a diachronous deposition history of these groups, where the Yaounde Group is pre-kinematic while the sedimentary and magmatic rocks of the Lom basin are syn-kinematic. Sinistral shear movements along the CCSZ and Sanaga faults are correlated with metamorphism and thrusting of the Yaounde granulites onto the Congo craton, on one hand, and to the opening of the Lom pull-apart basin, oblique to the shear zone, on the other. Kinematic interactions between shear and thrust movements characterize transpression, whereas interactions between shear and oblique normal fault movements characterize transtension. Resulting kinematic indicators show that the Lom basin represents a sinistral transtensional relay of the Sanaga fault. Greenschist-facies metamorphism in the Lom Group rocks dominantly affected by a monophase tectonic evolution were achieved during the late dextral shear movements along the Sanaga fault.

  3. Discharge and sediment loads at the Kings River Experimental Forest in the Southern Sierra Nevada of California

    Science.gov (United States)

    S.M. Eagan; C.T. Hunsaker; C.R. Dolanc; M.E. Lynch; C.R. Johnson

    2007-01-01

    The Kings River Experimental Watershed (KREW) is now in its third year of data collection on eight small perennial watersheds. We are collecting meteorology, stream discharge, sediment load, water chemistry, shallow soil water chemistry, vegetation, macro-invertebrate, stream microclimate, and air quality data. This paper primarily examines discharge and sediment data...

  4. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Ethiopian Journal of Education and Sciences; Conflicts in Africa: Meaning, Causes, Impact and Solution African Research Review; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African Business Review; The Rise of ...

  5. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other ... search for an article by title, author/s or keywords,; and find other information ... Southern African Business Review; Income Tax Assignment under the ... Mizan Law Review; The Basis of Distinction Between Qualitative and Quantitative Research in ...

  6. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other ... search for an article by title, author/s or keywords,; and find other information ... Southern African Business Review; The Basis of Distinction Between Qualitative and ...

  7. Changing levels of heavy metal accumulation in birds at Tumacacori National Historic Park along the Upper Santa Cruz River Watershed in southern Arizona

    Science.gov (United States)

    van Riper, Charles; Lester, Michael B.

    2016-01-01

    National Parks and other protected areas can be influenced by contamination from outside their boundaries. This is particularly true of smaller parks and those in riparian ecosystems, a habitat that in arid environments provides critical habitat for breeding, migratory, and wintering birds. Animals living in contaminated areas are susceptible to adverse health effects as a result of long-term exposure and bioaccumulation of heavy metals. We investigated the distribution and cascading extent of heavy metal accumulation in Song Sparrows (Melospiza melodia) at Tumacacori National Historic Park (TUMA) along the upper Santa Cruz River watershed in southern Arizona. This study had three goals: (1) quantify the concentrations and distributional patterns of heavy metals in blood and feathers of Song Sparrows at Tumacacori National Historic Park, (2) quantify hematocrit values, body conditions (that is, residual body mass), and immune conditions of Song Sparrows in the park (3) compare our findings with prior studies at the park to assess the extent of heavy metal accumulation in birds at downstream sites after the 2009 wastewater treatment plant upgrade, and (4) quantify concentrations and distributional patterns of heavy metals in blood and feathers of Song Sparrows among six study sites throughout the upper Santa Cruz River watershed. This study design would allow us to more accurately assess song sparrow condition and blood parameters among sites with differing potential sources of contamination exposure, and how each location could have contributed to heavy metal levels of birds in the park.

  8. Feeding ecology of the freshwater crab Trichodactylus borellianus (Decapoda: Trichodactylidae in the floodplain of the Paraná River, southern South America

    Directory of Open Access Journals (Sweden)

    Verónica Williner

    2013-09-01

    Full Text Available Freshwater crabs are not commonly considered to be an important group in trophic webs, and this might be due to a lack of knowledge about their trophic roles in aquatic ecosystems. Trichodactylus borellianus is one of the most common and widely distributed freshwater crabs in the floodplains of the southern South American rivers. The main objective of the present study was to examine the trophic role of T. borellianus, in the floodplain of the Paraná River, and its relationships with the freshwater littoral community. The trophic spectrum of this species was characterized for both sexes and individuals of different sizes (adults and juveniles, throughout daily and seasonal cycles. Samples were collected from the aquatic vegetation of three shallow lakes. The diet composition and the feeding activity of T. borellianus were evaluated through the examination of the stomach contents and their degree of emptiness. This crab species consumed several plant and animal items, including amoebas, rotifers, oligochaetes, copepods, cladocerans, and insect larvae. Moreover, this species consumes filamentous and unicellular algae, diatoms, fungi, and macrophytic remains. The predatory habits varied with the season and time of day, and variations in the feeding activity of the juveniles and adults were detected and documented. The diversity of food items eaten by this crab suggests that its trophic role in the community as an omnivore and opportunistic predator provides a connection among several trophic levels from both aquatic and terrestrial communities.

  9. The impact of anthropogenic factors on the occurrence of molybdenum in stream and river sediments of central Upper Silesia (Southern Poland

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    Pasieczna Anna

    2017-12-01

    Full Text Available In our study, a detailed survey was conducted with the aim to determine the distribution and possible anthropogenic sources of molybdenum in river and stream sediments in the central Upper Silesian Industrial Region (Southern Poland, where for many years, iron and zinc smelters as well as coking and thermal power plants were operating. At the same time, this has also been a residential area with the highest population density in the country. Sediments (1397 samples in total were collected from rivers and streams, and analysed for the content of molybdenum and 22 other elements. ICP-AES and CV-AAS methods were applied for the determination of the content of elements. The studies revealed molybdenum content in the range of 5 mg·kg−1. The spatial distribution of molybdenum demonstrated by the geochemical map has indicated that the principal factor determining its content in sediments is the discharge of wastewater from steelworks and their slag heaps. Another source of this element in sediments has been the waste of the historical mining of zinc ore and metallurgy of this metal. Additionally, molybdenum migration from landfills of power plants, coal combustion and Mo emission to the atmosphere and dust fall-out have been significant inputs of Mo pollution to the sediments.

  10. Distribution and Source Apportionment of Polycyclic Aromatic Hydrocarbons (PAHs) in Forest Soils from Urban to Rural Areas in the Pearl River Delta of Southern China

    Science.gov (United States)

    Xiao, Yihua; Tong, Fuchun; Kuang, Yuanwen; Chen, Bufeng

    2014-01-01

    The upper layer of forest soils (0–20 cm depth) were collected from urban, suburban, and rural areas in the Pearl River Delta of Southern China to estimate the distribution and the possible sources of polycyclic aromatic hydrocarbons (PAHs). Total concentrations of PAHs in the forest soils decreased significantly along the urban–suburban–rural gradient, indicating the influence of anthropogenic emissions on the PAH distribution in forest soils. High and low molecular weight PAHs dominated in the urban and rural forest soils, respectively, implying the difference in emission sources between the areas. The values of PAH isomeric diagnostic ratios indicated that forest soil PAHs were mainly originated from traffic emissions, mixed sources and coal/wood combustion in the urban, suburban and rural areas, respectively. Principal component analysis revealed that traffic emissions, coal burning and residential biomass combustion were the three primary contributors to forest soil PAHs in the Pearl River Delta. Long range transportation of PAHs via atmosphere from urban area might also impact the PAHs distribution in the forest soils of rural area. PMID:24599040

  11. NOTES ON THE BIOLOGY AND ECOLOGY OF Sudanonautes floweri(DE MAN, 1901; CRUSTACEA: BRACHYURA: POTAMOIDEA: POTAMONAUTIDAE IN RIVER OGBOMWEN, SOUTHERN NIGERIA

    Directory of Open Access Journals (Sweden)

    FRANCIS O ARIMORO

    2008-01-01

    Full Text Available Investigation into some aspects of the biology and ecology of the freshwater crab, Sudanonautes floweri(De Man, 1901 in River Ogbomwen, Edo State, southern, Nigeria was carried out between February and July 2006. The study revealed that the crab species were widespread and abundant in the river. Abundance in terms of number and biomass was more during the wet season with at a peak in the months of June and July. The crab grew allometrically attaining a maximum total length and weight of 11.5 cm and 65 g respectively. The condition factor ranged from 8.60-9.45. These values did not vary with size and sex of the crab but showed seasonal variations. Females of Sudanonautes floweriwere more abundant although not significantly different from the expected 1:1 ratio. There were some sexually matured females with stages III gonad development. Fecundity estimate ranged from 400 to 650 eggs. The gonadosomatic index varied between 14.97 and 24.11%. Feeding habits varied slightly with size with larger sized crabs feeding on more and varied food particles. Generally, Sudanonautes flowerifed predominantly on detritus, crustaceans, fish, algae, filaments, diatoms and sand grains.

  12. Simulation of groundwater flow and streamflow depletion in the Branch Brook, Merriland River, and parts of the Mousam River watersheds in southern Maine

    Science.gov (United States)

    Nielsen, Martha G.; Locke, Daniel B.

    2015-01-01

    Watersheds of three streams, the Mousam River, Branch Brook, and Merriland River in southeastern Maine were investigated from 2010 through 2013 under a cooperative project between the U.S. Geological Survey and the Maine Geological Survey. The Branch Brook watershed previously had been deemed “at risk” by the Maine Geological Survey because of the proportionally large water withdrawals compared to estimates of the in-stream flow requirements for habitat protection. The primary groundwater withdrawals in the study area include a water-supply well in the headwaters of the system and three water-supply wells in the coastal plain near the downstream end of the system. A steady-state groundwater flow model was used to understand the movement of water within the system, to evaluate the water budget and the effect of groundwater withdrawals on streamflows, and to understand streamflow depletion in relation to the State of Maine’s requirements to maintain in-stream flows for habitat protection.

  13. Boards and governance in African national cricket organisations: An ...

    African Journals Online (AJOL)

    Southern African Business Review ... the boards of African national cricket organisations to enhance the understanding of board involvement in ... The research reports on the composition of the boards of African cricket organisations as well as ...

  14. The Quequén Salado river basin: Geology and biochronostratigraphy of the Mio-Pliocene boundary in the southern Pampean plain, Argentina

    Science.gov (United States)

    Beilinson, E.; Gasparini, G. M.; Tomassini, R. L.; Zárate, M. A.; Deschamps, C. M.; Barendregt, R. W.; Rabassa, J.

    2017-07-01

    The Quequén Salado river basin has been the focus of several contributions since the first decades of the XX century, namely dealing with the general geological features of the deposits and with the vertebrate remains. In this paper, the Neogene geological history documented by the Quequén Salado river exposures is reconstructed by means of stratigraphic, sedimentological and paleomagnetic studies along with the paleontological analysis of vertebrate remains. The study area is a crucial setting not only to better understand the evolution of the southern Pampas basin during the late Miocene-early Pliocene interval, but also to test the validity of the biochronologic and biostratigraphic schemes, especially the "Irenense". A geological model for the Quequén Salado river valley is proposed: a case of downcutting and headward erosion that contributes with a coherent interpretation to explain the spatial distribution of facies and fossil taxa: the younger in the distal sector of the Quequén Salado middle basin and the older in the lower basin. The sedimentary record is believed to represent the distal reaches of a distributary fluvial system that drained from the Ventania ranges. The stratigraphic section of Paso del Indio Rico results a key stratigraphic site to fully understand the stratigraphic nature of the boundary between the Miocene and the Pliocene (the Huayquerian and Montehermosan stages/ages). In this sense, two stratigraphically superposed range zones have been recognized in the area: Xenodontomys ellipticus Range Zone (latest Miocene-early Pliocene; late Huayquerian), and Eumysops laeviplicatus Range Zone (early Pliocene; Montehermosan). Taking into account the available geological and paleontological evidences, the "Irenense" would not represent a valid biostratigraphic unit, since, according to the geological model here proposed, it would be represented by elements of the Xenodontomys ellipticus Range Zone in the lower QS basin and by elements of the

  15. Warming of the Indian Ocean threatens eastern and southern African food security but could be mitigated by agricultural development

    Science.gov (United States)

    Funk, Chris C.; Dettinger, Michael D.; Michaelsen, Joel C.; Verdin, James P.; Brown, Molly E.; Barlow, Mathew; Hoell, Andrew

    2008-01-01

    Since 1980, the number of undernourished people in eastern and southern Africa has more than doubled. Rural development stalled and rural poverty expanded during the 1990s. Population growth remains very high, and declining per-capita agricultural capacity retards progress toward Millennium Development goals. Analyses of in situ station data and satellite observations of precipitation have identified another problematic trend: main growing-season rainfall receipts have diminished by ???15% in food-insecure countries clustered along the western rim of the Indian Ocean. Occurring during the main growing seasons in poor countries dependent on rain-fed agriculture, these declines are societally dangerous. Will they persist or intensify? Tracing moisture deficits upstream to an anthropogenically warming Indian Ocean leads us to conclude that further rainfall declines are likely. We present analyses suggesting that warming in the central Indian Ocean disrupts onshore moisture transports, reducing continental rainfall. Thus, late 20th-century anthropogenic Indian Ocean warming has probably already produced societally dangerous climate change by creating drought and social disruption in some of the world's most fragile food economies. We quantify the potential impacts of the observed precipitation and agricultural capacity trends by modeling 'millions of undernourished people' as a function of rainfall, population, cultivated area, seed, and fertilizer use. Persistence of current tendencies may result in a 50% increase in undernourished people by 2030. On the other hand, modest increases in per-capita agricultural productivity could more than offset the observed precipitation declines. Investing in agricultural development can help mitigate climate change while decreasing rural poverty and vulnerability. ?? 2008 by The National Academy of Sciences of the USA.

  16. Warming of the Indian Ocean threatens eastern and southern African food security but could be mitigated by agricultural development.

    Science.gov (United States)

    Funk, Chris; Dettinger, Michael D; Michaelsen, Joel C; Verdin, James P; Brown, Molly E; Barlow, Mathew; Hoell, Andrew

    2008-08-12

    Since 1980, the number of undernourished people in eastern and southern Africa has more than doubled. Rural development stalled and rural poverty expanded during the 1990s. Population growth remains very high, and declining per-capita agricultural capacity retards progress toward Millennium Development goals. Analyses of in situ station data and satellite observations of precipitation have identified another problematic trend: main growing-season rainfall receipts have diminished by approximately 15% in food-insecure countries clustered along the western rim of the Indian Ocean. Occurring during the main growing seasons in poor countries dependent on rain-fed agriculture, these declines are societally dangerous. Will they persist or intensify? Tracing moisture deficits upstream to an anthropogenically warming Indian Ocean leads us to conclude that further rainfall declines are likely. We present analyses suggesting that warming in the central Indian Ocean disrupts onshore moisture transports, reducing continental rainfall. Thus, late 20th-century anthropogenic Indian Ocean warming has probably already produced societally dangerous climate change by creating drought and social disruption in some of the world's most fragile food economies. We quantify the potential impacts of the observed precipitation and agricultural capacity trends by modeling "millions of undernourished people" as a function of rainfall, population, cultivated area, seed, and fertilizer use. Persistence of current tendencies may result in a 50% increase in undernourished people by 2030. On the other hand, modest increases in per-capita agricultural productivity could more than offset the observed precipitation declines. Investing in agricultural development can help mitigate climate change while decreasing rural poverty and vulnerability.

  17. Three-dimensional mathematical model to simulate groundwater flow in the lower Palar River basin, southern India

    Science.gov (United States)

    Senthilkumar, M.; Elango, L.

    A three-dimensional mathematical model to simulate regional groundwater flow was used in the lower Palar River basin, in southern India. The study area is characterised by heavy ion of groundwater for agricultural, industrial and drinking water supplies. There are three major pumping stations on the riverbed apart from a number of wells distributed over the area. The model simulates groundwater flow over an area of about 392 km2 with 70 rows, 40 columns, and two layers. The model simulated a transient-state condition for the period 1991-2001. The model was calibrated for steady- and transient-state conditions. There was a reasonable match between the computed and observed heads. The transient model was run until the year 2010 to forecast groundwater flow under various scenarios of overpumping and less recharge. Based on the modelling results, it is shown that the aquifer system is stable at the present rate of pumping, excepting for a few locations along the coast where the groundwater head drops from 0.4 to 1.81 m below sea level during the dry seasons. Further, there was a decline in the groundwater head by 0.9 to 2.4 m below sea level in the eastern part of the area when the aquifer system was subjected to an additional groundwater withdrawal of 2 million gallons per day (MGD) at a major pumping station. Les modèles mathématiques en trois dimensions de l'écoulement souterrain régional sont très utiles pour la gestion des ressources en eau souterraine, car ils permettent une évaluation des composantes des processus hydrologiques et fournissent une description physique de l'écoulement de l'eau dans un aquifère. Une telle modélisation a été entreprise sur une partie du bassin inférieur de la rivière Palar, dans le sud de l'Inde. La zone d'étude est caractérisée par des prélèvements importants d'eau souterraine pour l'agriculture, l'industrie et l'eau potable. Il existe trois grandes stations de pompage sur la rivière en plus d'un certain nombre

  18. Antibiogram, Adhesive Characteristics, and Incidence of Class 1 Integron in Aeromonas Species Isolated from Two South African Rivers

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    Isoken H. Igbinosa

    2013-01-01

    Full Text Available Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered from the two rivers. All Aeromonas isolates were resistant to oxacillin, penicillin, clindamycin, cephalothin, vancomycin, and rifamycin, while appreciable susceptibilities (89.3 : 94.1%, 82.1 : 94.1%, 85.7 : 88.2%, and 92.9 : 88.2% were observed against ciprofloxacin, chloramphenicol, nitrofurantoin, and gentamicin from Kat and Tyume rivers, respectively. Multiple antibiotic resistance (MAR indices ranged from 0.016 to 0.044 for the two rivers. Class 1 integron was detected in about 20% of the isolates, and all the isolates except one showed ability to produce biofilm in vitro as weak producers (53.33%, moderate producers (15.56%, and strong producers (28.9%. This investigation provides a baseline data on antibiotic resistance as well as the adhesive characteristics of Aeromonas isolates from Tyume and Kat rivers in the Eastern Cape province of South Africa.

  19. Some southern African plant species used to treat helminth infections in ethnoveterinary medicine have excellent antifungal activities

    Directory of Open Access Journals (Sweden)

    Adamu Mathew

    2012-11-01

    Full Text Available Abstract Background Diseases caused by microorganisms and parasites remain a major challenge globally and particularly in sub-Saharan Africa to man and livestock. Resistance to available antimicrobials and the high cost or unavailability of antimicrobials complicates matters. Many rural people use plants to treat these infections. Because some anthelmintics e.g. benzimidazoles also have good antifungal activity we examined the antifungal activity of extracts of 13 plant species used in southern Africa to treat gastrointestinal helminth infections in livestock and in man. Methods Antifungal activity of acetone leaf extracts was determined by serial microdilution with tetrazolium violet as growth indicator against Aspergillus fumigatus, Cryptococcus neoformans and Candida albicans. These pathogens play an important role in opportunistic infections of immune compromised patients. Cytotoxicity was determined by MTT cellular assay. Therapeutic indices were calculated and selectivity for different pathogens determined. We proposed a method to calculate the relation between microbicidal and microbistatic activities. Total activities for different plant species were calculated. Results On the whole, all 13 extracts had good antifungal activities with MIC values as low as 0.02 mg/mL for extracts of Clausena anisata against Aspergillus fumigatus and 0.04 mg/mL for extracts of Zanthoxylum capense, Clerodendrum glabrum, and Milletia grandis, against A. fumigatus. Clausena anisata extracts had the lowest cytotoxicity (LC50 of 0.17 mg/mL, a reasonable therapeutic index (2.65 against A. fumigatus. It also had selective activity against A. fumigatus, an overall fungicidal activity of 98% and a total activity of 3395 mL/g against A. fumigatus. This means that 1 g of acetone leaf extract can be diluted to 3.4 litres and it would still inhibit the growth. Clerodendrum glabrum, Zanthoxylum capense and Milletia grandis extracts also yielded promising results

  20. Austrian phase on the northern African margin inferred from sequence stratigraphy and sedimentary records in southern Tunisia (Chotts and Djeffara areas)

    Science.gov (United States)

    Lazzez, Marzouk; Zouaghi, Taher; Ben Youssef, Mohamed

    2008-08-01

    A multidisciplinary study concerning Aptian and Albian deposits is reported from petroleum wells and the exposed section. The biostratigraphic and sedimentological analysis defined four sedimentary units. Well-logging signals' analysis allows us to refine the record resolution on Aptian series and reveals, in the Djeffara field, a transgressive system tract (TST) and a highstand system tract (HST). Exceptionally, the first sequence (S1) in the Mareth 1 well and the fifth sequence in the two wells Mareth 1 and Gourine 1 reveal the lower-stand system tract (LST). The unconformities characterized by the absence of Upper Aptian (Clansayesian) and Lower to Middle Albian deposits signed by a significant gamma-ray reduction. The Middle and Upper Albian is represented by only one deposit sequence (S6) in Mareth 1. Towards the south, in the Gourine well, two deposit sequences were identified (S6 and S7); to specify the Aptian and Albian evolution of the deposit sequences, a tentative correlation has been established between the Chotts and Djeffara areas. This correlation allows us to characterize the sedimentary unconformities related to the tectonics and eustatic events. The Chotts and the Djeffara deposition areas were developed, characterized by an irregular subsidence and separated by the Tebaga Medenine high area. The Aptian-Albian subsidence platform of southern Tunisia may be considered as a block diagram of environmental deposit with regressive and transgressive trends, showing the impact of tectonic deformations on the palaeogeographic evolution of southeastern Tunisia during the Austrian phase. This study also must be replaced within regional structural patterns that may explain both the sequential and sedimentological evolution of the area. Deformations regionally identified are integrated in the more general context of both Tethyan and Atlantic areas related to the drift of the African platform.

  1. Clinical practice guidelines within the Southern African development community: a descriptive study of the quality of guideline development and concordance with best evidence for five priority diseases

    Science.gov (United States)

    2012-01-01

    Background Reducing the burden of disease relies on availability of evidence-based clinical practice guidelines (CPGs). There is limited data on availability, quality and content of guidelines within the Southern African Development Community (SADC). This evaluation aims to address this gap in knowledge and provide recommendations for regional guideline development. Methods We prioritised five diseases: HIV in adults, malaria in children and adults, pre-eclampsia, diarrhoea in children and hypertension in primary care. A comprehensive electronic search to locate guidelines was conducted between June and October 2010 and augmented with email contact with SADC Ministries of Health. Independent reviewers used the AGREE II tool to score six quality domains reporting the guideline development process. Alignment of the evidence-base of the guidelines was evaluated by comparing their content with key recommendations from accepted reference guidelines, identified with a content expert, and percentage scores were calculated. Findings We identified 30 guidelines from 13 countries, publication dates ranging from 2003-2010. Overall the 'scope and purpose' and 'clarity and presentation' domains of the AGREE II instrument scored highest, median 58%(range 19-92) and 83%(range 17-100) respectively. 'Stakeholder involvement' followed with median 39%(range 6-75). 'Applicability', 'rigour of development' and 'editorial independence' scored poorly, all below 25%. Alignment with evidence was variable across member states, the lowest scores occurring in older guidelines or where the guideline being evaluated was part of broader primary healthcare CPG rather than a disease-specific guideline. Conclusion This review identified quality gaps and variable alignment with best evidence in available guidelines within SADC for five priority diseases. Future guideline development processes within SADC should better adhere to global reporting norms requiring broader consultation of stakeholders

  2. Phytoplankton of the portion of the Paranapanema River to be dammed for construction of the Rosana Hydroelectric Plant, Sao Paulo State, Southern Brazil; Fitoplancton do trecho a represar do Rio Paranapanema (Usina Hidreletrica de Rosana), Estado de Sao Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Bicudo, Carlos E. de M.; Bicudo, Denise de C.; Castro, Ana Alice J. de; Picelli-Vicentim, M. Marcina [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Ficologia

    1992-12-31

    The phytoplankton community of the 120 Km long portion of the Paranapanema River located between the Salto Grande Hydroelectric Plant reservoir and the river mouth at the Parana River is surveyed. This part of the river will be dammed for construction of the Rosana hydroelectric System in the State of Sao Paulo, southern Brazil. An inventory was completed for 4 collecting stations, and based on the study of 48 samples gathered bimonthly during the period from November 1985 to September 1986. Each collection is represented by a net concentrated and a raw total phytoplankton sample. Except for the Bacillariophyceae, study of which is still in progress, the other classes present were the following in order of their local representation: Chlorophyceae with 23 taxa, Zygnemaphyceae (= Cyanophyceae) with 9, Tribophyceace (= Xanthophyceae) with 2 each one, and Oedogoniophyceae, Euglenophyceae and Chrysophyceae with a single taxon each, to a total of 55 taxa identified. (author) 27 refs., 6 figs.

  3. The Quaternary uplift history of central southern England: evidence from the terraces of the Solent River system and nearby raised beaches

    Science.gov (United States)

    Westaway, Rob; Bridgland, David; White, Mark

    2006-09-01

    We have used fluvial (Solent River system) and marine terraces to reconstruct the uplift history of central southern England. In the case of the former, we make the assumption that fluvial incision has been a direct response to surface uplift, with its precise timing controlled by climatic forcing of fluvial activity, such that height of terrace gravel above modern river is a consequence of uplift since deposition. In the case of the marine sequence, we take the height of interglacial raised beaches above a calculated contemporaneous sea-level as a measure of uplift, the calculation involving an adjustment from modern sea-level using the deep oceanic oxygen isotope signal as an indication of global ice volume at the time of deposition. This exercise requires some degree of dating constraint, which is problematic for both environments. The Solent terraces have yielded little biostratigraphical evidence, whereas the south coast raised beaches have either been poorly exposed in recent years or their ages have been controversial because of disputes between biostratigraphy and geochronological data. We have supplemented the evidence available from these sources by using key aspects of the archaeological record as dating constraints, in particular the first appearances of Levallois technique (a marker for MIS 9-8) and of bout coupé handaxes (MIS 3). The first of these has been particularly useful in modelling of the Middle Pleistocene parts of the river terrace staircases of the Solent system. In undertaking this reappraisal, we have noted several inconsistencies and disagreements between past correlation schemes for the terraces of the Solent and its various tributaries. We find that versions involving shallower downstream gradients in the main Solent River are most likely to be correct and that revisions on this basis solve a number of problems in interpretation encountered previously. Our results show that most of this region has uplifted by ˜70 m since the late

  4. DECREASING OF WATER TROPHY IN CASCADE SYSTEMS, ON EXAMPLE OF THE SOŁA RIVER DAM CASCADE (SOUTHERN POLAND

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    Ewa Jachniak

    2014-10-01

    Full Text Available In this thesis the subject of water self-purification in cascade systems of water reservoirs was engaged. The results of hydrobiological research of three dam reservoirs (Tresna, Porąbka and Czaniec, creating the Soła river dam cascade were presented. The trophic status of these reservoirs was defined on the grounds of the concentration of chlorophyll a, biomass of phytoplankton and occurrence of indicating species of planktonic algae. The results of research indicated on decreasing of water trophy in the layout from the highest into the lowest reservoir of the cascade. The average concentrations of chlorophyll a amounted appropriately 19,99 μg·dm-3, 8,74 μg·dm-3 and 4,29 μg·dm-3, instead the average biomass of phytoplankton amounted appropriately 4,1 mg·dm-3, 3,4 mg·dm-3 and 0,1 mg·dm-3. The observed species of algae confirmed occurrence of differences between reservoirs. In Tresna reservoir more species of phytoplankton indicating for eutrophy were thrived, instead in Porąbka and Czaniec reservoirs the species occurring in oligomesotrophic water thrived. Water self-purification in the Soła river dam cascade expressed decreasing of their fertility is important for water management of the region, because the Czaniec reservoir fulfill a function of water-supply reservoir.

  5. New taxa of Hesperantha (Iridaceae: Crocoideae from the southern African winter rainfall region and a review of the H. pilosa complex

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    P. Goldblatt

    2013-01-01

    Full Text Available The southern and tropical Africa genus Hesperantha Ker Gawl., now with 85 species, is distinguished in subfam. Crocoideae by the style dividing into relatively long, usually laxly spreading style branches at or shortly below the mouth of the perianth tube (rarely well within the tube or above the mouth of the tube and, with a few exceptions, by hard, woody corm tunics. We describe three new species here. H. dolomitica Goldblatt & J.C.Manning, a narrow endemic of limestone outcrops on slopes north of the Vars River in the Knersvlakte, Western Cape, has the bell-shaped corms characteristic of the small sect. Hesperantha but is distinctive in the section in its pure white perianth with relatively long tube and soft-textured, falcate to distally trailing leaves. H. laxifolia Goldblatt & J.C.Manning from the Pakhuis Mtns, Western Cape, stands out in sect. Hesperantha in its prostate, somewhat succulent foliage leaves, and spikes of 2–5 white flowers with unusually short filaments less than 1 mm long and particularly short anthers, ± 4 mm long. The short style branches, ± 4 mm long, remain suberect rather than laxly spreading. H. secunda Goldblatt & J.C.Manning from the Roggeveld Escarpment, Northern Cape, has until now been included in H. pilosa but differs in its secund spike of nodding flowers with short style branches, and leaves with broadly winged margins. We also recognize a new subsp. bracteolata (R.C.Foster Goldblatt & J.C.Manning of H. pilosa (L.f. Ker Gawl. for populations of plants with diurnal flowers with usually blue or purple (occasionally white tepals lacking dark pigmentation on the reverse. With additional material to hand, we reduce blue-flowered H. ciliolata Goldblatt to synonymy in subsp. bracteolata and report range extensions for H. pilosa subsp. pilosa, now recorded as far east as the Langeberg near Cloete’s Pass.

  6. Spatial and temporal dynamics of sediment in contrasted mountainous watersheds (Mexican transvolcanic belt and French Southern Alps) combining river gauging, elemental geochemistry and fallout radionuclides

    Science.gov (United States)

    Evrard, O.; Navratil, O.; Gratiot, N.; Némery, J.; Duvert, C.; Ayrault, S.; Lefèvre, I.; Legout, C.; Bonté, P.; Esteves, M.

    2009-12-01

    In mountainous environments, an excessive fine sediment supply to the rivers typically leads to an increase in water turbidity, contaminant transport and a rapid filling of reservoirs. This situation is particularly problematic in regions where water reservoirs are used to provide drinking water to large cities (e.g. in central Mexico) or where stream water is used to run hydroelectric power plants (e.g. in the French Southern Alps). In such areas, sediment source areas first need to be delineated and sediment fluxes between hillslopes and the river system must be better understood before implementing efficient erosion control measures. In this context, the STREAMS (« Sediment Transport and Erosion Across MountainS ») project funded by the French National Research Agency (ANR) aims at understanding the spatial and temporal dynamics of sediment at the scale of mountainous watersheds (between 500 - 1000 km2) located in contrasted environments. This 3-years study is carried out simultaneously in a volcanic watershed located in the Mexican transvolcanic belt undergoing a subhumid tropical climate, as well as in a sedimentary watershed of the French Southern Alps undergoing a transitional climate with Mediterranean and continental influences. One of the main specificities of this project consists in combining traditional monitoring techniques (i.e. installation of river gauges, turbidimeters and sediment samplers in several sub-catchments) and sediment fingerprinting using elemental geochemistry (measured by Instrumental Neutron Activation Analysis - INAA - and Inductively Coupled Plasma - Mass Spectrometry - ICP-MS) and fallout radionuclides (measured by gamma spectrometry). In the French watershed, geochemical analysis allows outlining different sediment sources (e.g. the contribution of calcareous vs. marl-covered sub-watersheds). Radionuclide ratios (e.g.Be-7/Cs-137) allow identifying the dominant erosion processes occurring within the watershed. Areas mostly

  7. Serological evidence for Saint Louis encephalitis virus in free-ranging New World monkeys and horses within the upper Paraná River basin region, Southern Brazil

    Directory of Open Access Journals (Sweden)

    Walfrido Kühl Svoboda

    2014-06-01

    Full Text Available Introduction Saint Louis encephalitis virus (SLEV primarily occurs in the Americas and produces disease predominantly in humans. This study investigated the serological presence of SLEV in nonhuman primates and horses from southern Brazil. Methods From June 2004 to December 2005, sera from 133 monkeys (Alouatta caraya, n=43; Sapajus nigritus, n=64; Sapajus cay, n=26 trap-captured at the Paraná River basin region and 23 blood samples from farm horses were obtained and used for the serological detection of a panel of 19 arboviruses. All samples were analyzed in a hemagglutination inhibition (HI assay; positive monkey samples were confirmed in a mouse neutralization test (MNT. Additionally, all blood samples were inoculated into C6/36 cell culture for viral isolation. Results Positive seroreactivity was only observed for SLEV. A prevalence of SLEV antibodies in sera was detected in Alouatta caraya (11.6%; 5/43, Sapajus nigritus (12.5%; 8/64, and S. cay (30.8%; 8/26 monkeys with the HI assay. Of the monkeys, 2.3% (1/42 of A. caraya, 6.3% 94/64 of S. nigritus, and 15.4% (4/26 of S. cay were positive for SLEV in the MNT. Additionally, SLEV antibodies were detected by HI in 39.1% (9/23 of the horses evaluated in this study. Arboviruses were not isolated from any blood sample. Conclusions These results confirmed the presence of SLEV in nonhuman primates and horses from southern Brazil. These findings most likely represent the first detection of this virus in nonhuman primates beyond the Amazon region. The detection of SLEV in animals within a geographical region distant from the Amazon basin suggests that there may be widespread and undiagnosed dissemination of this disease in Brazil.

  8. Biomarkers of Oxidative Stress and Heavy Metal Levels as Indicators of Environmental Pollution in African Cat Fish (Clarias gariepinus from Nigeria Ogun River

    Directory of Open Access Journals (Sweden)

    Y. R. Ajimoko

    2007-06-01

    Full Text Available Levels of Zn, Cu, Cd, As, and Pb in the kidney, Liver, Gills and Heart of African cat fish (Clarias gariepinus from the Ogun River in Ogun State located close to six major industries in the South Western part of Nigeria, were determined using Bulk Scientific Atomic Absorption Spectrophotometer. Fishes were also collected from Government owned fish farm in Agodi, Ibadan which was considered a reference site. The activities of superoxide dismutase (SOD, catalase (CAT, glutathione S-transferase (GST, glutathione (GSH concentration and malondialdehyde (MDA formation were also determined. The trend of accumulation of the metals in the organs is as follows: Heart - Zn > Cu > Pb > As > Cd; Gills - Zn > Cu > Pb > Cd > As; Kidney - Zn > Cu > Pb > As > Cd; Liver -Zn > Cu > Pb > As > Cd. The order of concentration of the metals in the organs is as follows: Arsenite - Kidney > Liver > Gills > Heart; Zinc - Gills > Liver > Kidney > Heart; Lead- Liver > Kidney > Gills > Heart; Copper- Kidney > Liver > Gills > Heart; Cadmium > Liver > Gills > Kidney > Heart. The levels of heavy metals ranged between 0.25-8.96 ppm in the heart, 0.69- 19.05 ppm in the kidneys, 2.10-19.75 ppm in the liver and 1.95-20.35 ppm in the gills. SOD activity increased by 61% in the liver, 50% in the kidney and in the heart by 28 % while a significant decrease (44% was observed in the gill of Clarias gariepinus from Ogun river compared to that Agodi fish farm (P<0.001. On the contrary there was 46%, 41%, 50% and 19% decrease in CAT activity in the liver, kidney, gills and heart respectively. The levels of GST activities in the liver, kidney and heart of Clarias gariepinus from Ogun river increased by 62%, 72% and 37% respectively (P<0.001 whereas there was a significant decrease (41% in the gills (P<0.05 compared to that from the Agodi fish farm. GSH concentration increased by 81%, 83% and 53% in the liver, kidney and heart respectively but decreased by 44% in the gills. MDA levels of

  9. Biomarkers of Oxidative Stress and Heavy Metal Levels as Indicators of Environmental Pollution in African Cat Fish (Clarias gariepinus) from Nigeria Ogun River

    Science.gov (United States)

    Farombi, E. O.; Adelowo, O. A.; Ajimoko, Y. R.

    2007-01-01

    Levels of Zn, Cu, Cd, As, and Pb in the kidney, Liver, Gills and Heart of African cat fish (Clarias gariepinus) from the Ogun River in Ogun State located close to six major industries in the South Western part of Nigeria, were determined using Bulk Scientific Atomic Absorption Spectrophotometer. Fishes were also collected from Government owned fish farm in Agodi, Ibadan which was considered a reference site. The activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), glutathione (GSH) concentration and malondialdehyde (MDA) formation were also determined. The trend of accumulation of the metals in the organs is as follows: Heart - Zn > Cu > Pb > As > Cd; Gills - Zn > Cu > Pb > Cd > As; Kidney - Zn > Cu > Pb > As > Cd; Liver -Zn > Cu > Pb > As > Cd. The order of concentration of the metals in the organs is as follows: Arsenite - Kidney > Liver > Gills > Heart; Zinc - Gills > Liver > Kidney > Heart; Lead- Liver > Kidney > Gills > Heart; Copper- Kidney > Liver > Gills > Heart; Cadmium > Liver > Gills > Kidney > Heart. The levels of heavy metals ranged between 0.25–8.96 ppm in the heart, 0.69– 19.05 ppm in the kidneys, 2.10–19.75 ppm in the liver and 1.95–20.35 ppm in the gills. SOD activity increased by 61% in the liver, 50% in the kidney and in the heart by 28 % while a significant decrease (44%) was observed in the gill of Clarias gariepinus from Ogun river compared to that Agodi fish farm (PCAT activity in the liver, kidney, gills and heart respectively. The levels of GST activities in the liver, kidney and heart of Clarias gariepinus from Ogun river increased by 62%, 72% and 37% respectively (Pfish farm. GSH concentration increased by 81%, 83% and 53% in the liver, kidney and heart respectively but decreased by 44% in the gills. MDA levels of Clarias gariepinus were significantly (Pfish farm. Overall, the results demonstrate that alteration in the antioxidant enzymes, glutathione system and induction of lipid peroxidation

  10. Study of the growth, reproductive biology and abundance for invasive shrimps Palaemon elegans Rathke from Garmat Ali river Basrah, Southern Iraq

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    Khaled Khasaf Al-Khafaji

    2016-07-01

    Full Text Available Objective: To describe the growth, reproductive biology and abundance of the population of invasive shrimps Palaemon elegans (P. elegans in one of the branches of Garmat Ali river at Basrah, Southern Iraq. Methods: Monthly samples of the prawn P. elegans were collected with a bottom hand net (40 cm, 0.5 mm mesh hauled over a distance of 10 m. A simple random sampling was conducted monthly between December 2012 and November 2013. Results: Seasonal changes were observed in the composition of the population of the species during the study year with the highest abundance in 2013 and the lowest abundance for the males was reported in January and for the females occurred in June. Salinity showed a significant correlation with the abundance of shrimps at the sampling site. The largest female measured 67.90 mm while the corresponding value for males was 61.31 mm. The proportion of ovigerous adults rose during spring season to peak on about July and ovigerous prawns were taken in all months of the year. The sex ratio indicated a preponderance of females over males in all months in the study period. Each females produced around 36–1324 eggs and the incubation period lasted for 11–14 days at 17–29 °C. Conclusions: The results of the present study indicate that this species has a wide distribution range, high density, and great reproduction potential. This study reveals the lack of researches on this species in environments of Shatt Al-Arab river and its branches. Thus, P. elegans has most likely formed a permanent population in all the brackish waters in Basrah area.

  11. Combined effect of boundary layer recirculation factor and stable energy on local air quality in the Pearl River Delta over southern China.

    Science.gov (United States)

    Li, Haowen; Wang, Baomin; Fang, Xingqin; Zhu, Wei; Fan, Qi; Liao, Zhiheng; Liu, Jian; Zhang, Asi; Fan, Shaojia

    2018-03-01

    Atmospheric boundary layer (ABL) has a significant impact on the spatial and temporal distribution of air pollutants. In order to gain a better understanding of how ABL affects the variation of air pollutants, atmospheric boundary layer observations were performed at Sanshui in the Pearl River Delta (PRD) region over southern China during the winter of 2013. Two types of typical ABL status that could lead to air pollution were analyzed comparatively: weak vertical diffusion ability type (WVDAT) and weak horizontal transportation ability type (WHTAT). Results show that (1) WVDAT was featured by moderate wind speed, consistent wind direction, and thick inversion layer at 600~1000 m above ground level (AGL), and air pollutants were restricted in the low altitudes due to the stable atmospheric structure; (2) WHTAT was characterized by calm wind, varied wind direction, and shallow intense ground inversion layer, and air pollutants accumulated in locally because of strong recirculation in the low ABL; (3) recirculation factor (RF) and stable energy (SE) were proved to be good indicators for horizontal transportation ability and vertical diffusion ability of the atmosphere, respectively. Combined utilization of RF and SE can be very helpful in the evaluation of air pollution potential of the ABL. Air quality data from ground and meteorological data collected from radio sounding in Sanshui in the Pearl River Delta showed that local air quality was poor when wind reversal was pronounced or temperature stratification state was stable. The combination of horizontal and vertical transportation ability of the local atmosphere should be taken into consideration when evaluating local environmental bearing capacity for air pollution.

  12. ESR dating of glacial tills of Baishuihe river on the southern slope of Lenglongling in the eastern part of Qilian Mountains

    International Nuclear Information System (INIS)

    Zhao Jingdong; Zhou Shangzhe; Shi Zhengtao; Zhang Shiqiang; Cui Jianxin; Xu Liubing; Ye Yuguang

    2001-01-01

    Baishuihe River is a tributary of Datong River, located on the southern slope of Lenglongling in the eastern part of the Qilian Mountains. An integral end till remains at the entrance of the valley. There is a push moraine in the till section. Three samples were derived from this section. Two samples were collected at the front of the push moraine and another sample (near the push moraine) collected from the rear of it, ESR ages were 73.0 ka, 55.8 ka, 36.7 ka respectively. The ESR ages being consistent with the relationship of deposits. The ages before the push moraine were correlated to the deep-sea oxygen isotope stage 4 within 10% deviation. Based on them, the authors could determine the till before the push moraine were formed in the early period of Last Glaciation. Comparing the ESR age of LS-5 with the results of previous 14 C, the authors found that the ESR age was older. Through the error correction, the authors concluded: the existing push moraine distorted the till around it, mixing the super-glacial till, englacial till and subglacial till together. The authors considered: the main reason influencing the ESR age was that the englacial till and the subglacial till were not exposed completely before they deposited. Although the result of LS-5 was older than the previous 14 C, combining the ESR age and the relationship of deposit and the existing 14 C ages, the authors inferred that the rear of the push moraine was deposited in the later period of the last glaciation and was correlated to the deep-sea oxygen isotope stage 2. At the same time, the conclusion once again proved the previous scholars' conclusion. This shows the ESR technique may be applied to glacial till dating

  13. Patterning and predicting aquatic insect richness in four West-African coastal rivers using artificial neural networks

    OpenAIRE

    Edia E.O.; Gevrey M.; Ouattara A.; Brosse S.; Gourène G.; Lek S.

    2010-01-01

    Despite their importance in stream management, the aquatic insect assemblages are still little known in West Africa. This is particularly true in South-Eastern Ivory Coast, where aquatic insect assemblages were hardly studied. We therefore aimed at characterising aquatic insect assemblages on four coastal rivers in South-Eastern Ivory Coast. Patterning aquatic insect assemblages was achieved using a Self-Organizing Map (SOM), an unsupervised Artificial Neural Networks (ANN) method. This metho...

  14. Distribution of naturally occurring radioactive materials in sediments from the Ebro river reservoir in Flix (Southern Catalonia, Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Mola, M.; Palomo, M.; Penalver, A.; Aguilar, C. [Departament de Quimica Analitica i Quimica Organica, Universitat Rovira i Virgili, Marcelli Domingo s/n, 43007 Tarragona (Spain); Unitat de Radioquimica Ambiental i Sanitaria (URAIS), Consorci d' Aiguees de Tarragona (CAT), Ctra Nacional 340, km 1094, 43895 L' Ampolla (Spain); Borrull, F., E-mail: francesc.borrull@urv.cat [Departament de Quimica Analitica i Quimica Organica, Universitat Rovira i Virgili, Marcelli Domingo s/n, 43007 Tarragona (Spain); Unitat de Radioquimica Ambiental i Sanitaria (URAIS), Consorci d' Aiguees de Tarragona (CAT), Ctra Nacional 340, km 1094, 43895 L' Ampolla (Spain)

    2011-12-30

    Industrial waste containing radioactive isotopes (from U-decay series) was released into Ebro river basin due to the activity of a dicalcium phosphate (DCP) plant for a period of more than two decades. Gross alpha, gross beta, {sup 40}K, {sup 226}Ra and {sup 210}Pb activities were determined in several sludge samples taken at different depths from different points in the area of influence of the DCP plant located in Flix. Samples were collected from two different zones: one in front of the DCP plant and the second in front of a wastewater treatment plant installed several years after the DCP plant. The data obtained verify the influence of industrial DCP production on radioactivity levels present in the area.

  15. Oligosarcus jacuiensis (Characiformes: Characidae, a new species from the Uruguay and Jacuí River basins, southern Brazil

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    Naércio Aquino Menezes

    Full Text Available The new species herein described, collected in the Jacuí and Uruguay River basins, Rio Grande do Sul, Brazil, can be distinguished from the already known species of the genus, but Oligosarcus jenynsii, O. perdido, O. acutirostris, O. solitarius and O. hepsetus, by the number of perforated lateral line scales. It shares with the first two species the absence of a premaxillary foramen, present in the last three species and differs from O. jenynsii by having a smaller orbital diameter and the tip of the pectoral fin failing to reach the pelvic-fin origin, and from O. perdido by the presence of more horizontal scale rows around the caudal peduncle.

  16. Climate and southern Africa's water-energy-food nexus

    Science.gov (United States)

    Conway, Declan; van Garderen, Emma Archer; Deryng, Delphine; Dorling, Steve; Krueger, Tobias; Landman, Willem; Lankford, Bruce; Lebek, Karen; Osborn, Tim; Ringler, Claudia; Thurlow, James; Zhu, Tingju; Dalin, Carole

    2015-09-01

    In southern Africa, the connections between climate and the water-energy-food nexus are strong. Physical and socioeconomic exposure to climate is high in many areas and in crucial economic sectors. Spatial interdependence is also high, driven, for example, by the regional extent of many climate anomalies and river basins and aquifers that span national boundaries. There is now strong evidence of the effects of individual climate anomalies, but associations between national rainfall and gross domestic product and crop production remain relatively weak. The majority of climate models project decreases in annual precipitation for southern Africa, typically by as much as 20% by the 2080s. Impact models suggest these changes would propagate into reduced water availability and crop yields. Recognition of spatial and sectoral interdependencies should inform policies, institutions and investments for enhancing water, energy and food security. Three key political and economic instruments could be strengthened for this purpose: the Southern African Development Community, the Southern African Power Pool and trade of agricultural products amounting to significant transfers of embedded water.

  17. Can Continental Shelf River Plumes in the Northern and Southern Gulf of Mexico Promote Ecological Resilience in a Time of Climate Change?

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    G. Paul Kemp

    2016-03-01

    Full Text Available Deltas and estuaries built by the Mississippi/Atchafalaya River (MAR in the United States and the Usumacinta/Grijalva River (UGR in Mexico account for 80 percent of all Gulf of Mexico (GoM coastal wetlands outside of Cuba. They rank first and second in freshwater discharge to the GoM and owe their natural resilience to a modular geomorphology that spreads risk across the coast-scape while providing ecosystem connectivity through shelf plumes that connect estuaries. Both river systems generate large plumes that strongly influence fisheries production over large areas of the northern and southern GoM continental shelves. Recent watershed process simulations (DLEM, MAPSS driven by CMIP3 General Circulation Model (GCM output indicate that the two systems face diverging futures, with the mean annual discharge of the MAR predicted to increase 11 to 63 percent, and that of the UGR to decline as much as 80 percent in the 21st century. MAR delta subsidence rates are the highest in North America, making it particularly susceptible to channel training interventions that have curtailed a natural propensity to shift course and deliver sediment to new areas, or to refurbish zones of high wetland loss. Undoing these restrictions in a controlled way has become the focus of a multi-billion-dollar effort to restore the MAR delta internally, while releasing fine-grained sediments trapped behind dams in the Great Plains has become an external goal. The UGR is, from an internal vulnerability standpoint, most threatened by land use changes that interfere with a deltaic architecture that is naturally resilient to sea level rise. This recognition has led to successful efforts in Mexico to protect still intact coastal systems against further anthropogenic impacts, as evidenced by establishment of the Centla Wetland Biosphere Preserve and the Terminos Lagoon Protected Area. The greatest threat to the UGR system, however, is an external one that will be imposed by the

  18. Bacillus velezensis sp. nov., a surfactant-producing bacterium isolated from the river Vélez in Málaga, southern Spain.

    Science.gov (United States)

    Ruiz-García, Cristina; Béjar, Victoria; Martínez-Checa, Fernando; Llamas, Inmaculada; Quesada, Emilia

    2005-01-01

    Two Gram-positive, endospore-forming bacterial strains, CR-502T and CR-14b, which produce surfactant molecules are described. Phenotypic tests and phylogenetic analyses showed these strains to be members of the genus Bacillus and related to the species Bacillus atrophaeus, Bacillus mojavensis, Bacillus subtilis, Bacillus vallismortis and Bacillus amyloliquefaciens, although they differ from these species in a number of phenotypic characteristics. DNA-DNA hybridization confirmed that they show less than 20 % hybridization with the above-mentioned species and therefore represent a novel species of Bacillus. The DNA G+C content is 46.4 mol% in strain CR-502T and 46.1 mol% in strain CR-14b. The main fatty acids in strain CR-502T are 15 : 0 anteiso (32.70 %), 15 : 0 iso (29.86 %) and 16 : 0 (13.41 %). The main quinone in strain CR-502T is MK-7 (96.6 %). In the light of the polyphasic evidence gathered in this study, it is proposed that these strains be classified as a novel species of the genus Bacillus, with the name Bacillus velezensis sp. nov. The type strain (CR-502T=CECT 5686T=LMG 22478T) was isolated from a brackish water sample taken from the river Vélez at Torredelmar in Málaga, southern Spain.

  19. Applications of multiscale change point detections to monthly stream flow and rainfall in Xijiang River in southern China, part I: correlation and variance

    Science.gov (United States)

    Zhu, Yuxiang; Jiang, Jianmin; Huang, Changxing; Chen, Yongqin David; Zhang, Qiang

    2018-04-01

    This article, as part I, introduces three algorithms and applies them to both series of the monthly stream flow and rainfall in Xijiang River, southern China. The three algorithms include (1) normalization of probability distribution, (2) scanning U test for change points in correlation between two time series, and (3) scanning F-test for change points in variances. The normalization algorithm adopts the quantile method to normalize data from a non-normal into the normal probability distribution. The scanning U test and F-test have three common features: grafting the classical statistics onto the wavelet algorithm, adding corrections for independence into each statistic criteria at given confidence respectively, and being almost objective and automatic detection on multiscale time scales. In addition, the coherency analyses between two series are also carried out for changes in variance. The application results show that the changes of the monthly discharge are still controlled by natural precipitation variations in Xijiang's fluvial system. Human activities disturbed the ecological balance perhaps in certain content and in shorter spells but did not violate the natural relationships of correlation and variance changes so far.

  20. Spatial, seasonal and ontogenetic variation in the diet of Astyanax aff. fasciatus (Ostariophysi: Characidae in an Atlantic Forest river, Southern Brazil

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    Luciano Lazzarini Wolff

    Full Text Available This study described the feeding habits of the characin Astyanax aff. fasciatus. The diet compositions of specimens from two sites (A and B on a river in Southern Brazil were compared according to the size of individuals and seasonal period. The collections were performed monthly from March 2005 to February 2006, where the stomach contents of 290 specimens were assessed. Food items for A. aff. fasciatus were basically composed of plants and insects, especially leaf fragments, seeds, fruits, filamentous algae, aquatic and terrestrial insects and insect fragments. At site A, the most common items were insect and plant fragments. Conversely at site B, plant fragments were more representative. In general, all items of animal origin showed the highest feeding index values at site A, whereas at site B detritus and grass items were more abundant. The composition of items varied seasonally, with higher diversity of items being recorded during the spring at both sites. Smaller individuals preferred items of animal origin, while the larger ones consumed mainly items of plant origin. According to its size, A. aff. fasciatus in this study may be considered a species with insectivorous tendencies when immature or herbivorous tendencies when adult. Nevertheless, its feeding habits may be flexible according to resource availability, showing wide ontogenetic, besides spatial and temporal variation.

  1. The first polluted river? Repeated copper contamination of fluvial sediments associated with Late Neolithic human activity in southern Jordan.

    Science.gov (United States)

    Grattan, J P; Adams, R B; Friedman, H; Gilbertson, D D; Haylock, K I; Hunt, C O; Kent, M

    2016-12-15

    The roots of pyrometallurgy are obscure. This paper explores one possible precursor, in the Faynan Orefield in southern Jordan. There, at approximately 7000cal. BP, banks of a near-perennial meandering stream (today represented by complex overbank wetland and anthropogenic deposits) were contaminated repeatedly by copper emitted by human activities. Variations in the distribution of copper in this sequence are not readily explained in other ways, although the precise mechanism of contamination remains unclear. The degree of copper enhancement was up to an order of magnitude greater than that measured in Pleistocene fluvial and paludal sediments, in contemporary or slightly older Holocene stream and pond deposits, and in the adjacent modern wadi braidplain. Lead is less enhanced, more variable, and appears to have been less influenced by contemporaneous human activities at this location. Pyrometallurgy in this region may have appeared as a byproduct of the activity practised on the stream-bank in the Wadi Faynan ~7000years ago. Copyright © 2016. Published by Elsevier B.V.

  2. Tracing of karstic waters in the southern part of the Frankish Alb between the rivers Anlauter, Altmuehl and Danube

    International Nuclear Information System (INIS)

    Behrens, H.; Seiler, K.P.

    1982-01-01

    It is reported about tracing investigations carried out at present in order to detect the passages of waste waters in the Karst of the Southern Frankish Alb. Tracings of karstic waters in the area of karstic watersheds can be performed successfully if the volume of the karstic ground waters equals the small quantities existing in the area between Altmuehl and Anlauter. In this region the karstic watershed is shifted by a strip of about 1 km width. This shift depends on the recharge and volume of the groundwater. All tracings between Altmuehl and Danube, carried out in the area of the karstic water shed, led to negative results, because in this region the volume of the karstic water is particularly large and since consequently the fluorescent tracers are extremely diluted in the waster masses. The amount of tracer material to be recovered ranges below 10%, if the ''most frequent distance velocity'' is below approximately 500 m/d. With higher distance velocities it is sometimes possible to recover more than 50% and even up to 100% of the dyes. (orig.) [de

  3. The effects of tertiary treated municipal wastewater on fish communities of a small river tributary in Southern Ontario, Canada

    International Nuclear Information System (INIS)

    Brown, Carolyn J.M.; Knight, Brendan W.; McMaster, Mark E.; Munkittrick, Kelly R.; Oakes, Ken D.; Tetreault, Grald R.; Servos, Mark R.

    2011-01-01

    Fish community changes associated with a tertiary treated municipal wastewater effluent outfall in the Speed River, Ontario, Canada, were evaluated at nine sites over two seasons (2008) using standardized electrofishing. Habitat evaluations were conducted to ensure that the riffle sites selected were physically similar. The fish community was dominated by several species of darters that differed in their response to the effluent outfall. There was a significant decrease in Greenside Darter (Etheostoma blennioides) but an increase in Rainbow Darter (E. caeruleum) abundance directly downstream of the outfall. Stable isotope signatures (δ 13 C and δ 15 N), which indicate shifts in energy utilization and flow, increased in Rainbow Darter downstream, but showed no change in Greenside Darter. Rainbow Darter may be exploiting a food source that is not as available at upstream sites giving them a competitive advantage over the Greenside Darter immediately downstream of the outfall. - Highlights: → Fish communities are altered by tertiary treated municipal wastewater exposure. → Relative abundance of the two dominant fish (darter) species changed downstream. → Differing stable isotope signatures in fish suggests shifting energy flow and diet. → The altered environment may allow resilient species a competitive advantage. → The system recovers quickly downstream. - Tertiary treated effluent altered fish community composition in a small receiving stream possibly as a result of altered availability of resources (diet) as indicated by stable isotopes.

  4. Rainfall Variability, Wetland Persistence, and Water–Carbon Cycle Coupling in the Upper Zambezi River Basin in Southern Africa

    Directory of Open Access Journals (Sweden)

    Lauren E. L. Lowman

    2018-05-01

    Full Text Available The Upper Zambezi River Basin (UZRB delineates a complex region of topographic, soil and rainfall gradients between the Congo rainforest and the Kalahari Desert. Satellite imagery shows permanent wetlands in low-lying convergence zones where surface–groundwater interactions are vigorous. A dynamic wetland classification based on MODIS Nadir BRDF-Adjusted Reflectance is developed to capture the inter-annual and seasonal changes in areal extent due to groundwater redistribution and rainfall variability. Simulations of the coupled water–carbon cycles of seasonal wetlands show nearly double rates of carbon uptake as compared to dry areas, at increasingly lower water-use efficiencies as the dry season progresses. Thus, wetland extent and persistence into the dry season is key to the UZRB’s carbon sink and water budget. Whereas groundwater recharge governs the expansion of wetlands in the rainy season under large-scale forcing, wetland persistence in April–June (wet–dry transition months is tied to daily morning fog and clouds, and by afternoon land–atmosphere interactions (isolated convection. Rainfall suppression in July–September results from colder temperatures, weaker regional circulations, and reduced instability in the lower troposphere, shutting off moisture recycling in the dry season despite high evapotranspiration rates. The co-organization of precipitation and wetlands reflects land–atmosphere interactions that determine wetland seasonal persistence, and the coupled water and carbon cycles.

  5. Catchment source contributions to the sediment-bound organic matter degrading salmonid spawning gravels in a lowland river, southern England

    International Nuclear Information System (INIS)

    Collins, A.L.; Williams, L.J.; Zhang, Y.S.; Marius, M.; Dungait, J.A.J.; Smallman, D.J.; Dixon, E.R.; Stringfellow, A.; Sear, D.A.; Jones, J.I.; Naden, P.S.

    2013-01-01

    The ingress of particulate material into freshwater spawning substrates is thought to be contributing to the declining success of salmonids reported over recent years for many rivers. Accordingly, the need for reliable information on the key sources of the sediment problem has progressed up the management agenda. Whilst previous work has focussed on apportioning the sources of minerogenic fine sediment degrading spawning habitats, there remains a need to develop procedures for generating corresponding information for the potentially harmful sediment-bound organic matter that represents an overlooked component of interstitial sediment. A source tracing procedure based on composite signatures combining bulk stable 13 C and 15 N isotope values with organic molecular structures detected using near infrared (NIR) reflectance spectroscopy was therefore used to assess the primary sources of sediment-bound organic matter sampled from artificial spawning redds. Composite signatures were selected using a combination of the Kruskal–Wallis H-test, principal component analysis and GA-driven discriminant function analysis. Interstitial sediment samples were collected using time-integrating basket traps which were inserted at the start of the salmonid spawning season and extracted in conjunction with critical phases of fish development (eyeing, hatch, emergence, late spawning). Over the duration of these four basket extractions, the overall relative frequency-weighted average median (± 95% confidence limits) source contributions to the interstitial sediment-bound organic matter were estimated to be in the order: instream decaying vegetation (39 ± road verges > septic tanks > farm manures

  6. Paleospring tufa deposition in the Kurkur Oasis region and implications for tributary integration with the River Nile in southern Egypt

    Science.gov (United States)

    Nicoll, Kathleen; Sallam, Emad S.

    2017-12-01

    Though southern Egypt is currently hyperarid, relict freshwater carbonate deposits called tufas near Kurkur (region centered at 23° 54‧ N, 32° 19‧ E) indicate that ambient rainwater-fed alkaline springs formerly sourced drainages in the Sinn El-Kaddab or Eocene scarp, and precipitated carbonate tufa deposits at waterfall cascades, pools, and streams. Petrographic analysis enables the reconstruction of a variety of vegetated microenvironments during Quaternary time. The Kurkur tufas are very porous rocks with an abundance of fossil plant casts and molds making up the petrofabrics at the macroscale. The tufas also preserve laminations of successive generations of calcified remains of microbes visible at the microscopic scale. Original carbonate framework architectures are massive carbonate structures to the decameter scale, with characteristic highly porous and permeable rock fabrics, including vegetation-rich phytoherms and stromatolite forms. The tufas are relatively pristine, preserving their original rock textures with minimal post-depositional alteration. Structural controls affecting the development of tufa deposits near Kurkur include fissure, cracks and fault planes that would have enhanced groundwater recharge and emergence of carbonate-saturated springs from perched aquifers above the Nubian Aquifer System during periods of greater effective rainfall in the past when the water table was significantly higher. The Kurkur tufas are relict archives from phases when groundwater discharge supported comparatively more vegetation than the modern day, and spring flows sustained baseflow in the Wadi Kurkur tributary of the Upper Nile. Episodes of tufa deposition along now-defunct tributaries therefore reflect phases of a more integrated Nile drainage system.

  7. Southern African Coastal vulnerability assessment

    CSIR Research Space (South Africa)

    Rautenbach, C

    2015-10-01

    Full Text Available or business. The CSIR coastal systems group uses specialist skills in coastal engineering, geographic engineering systems and numerical modelling to assess and map vulnerable coastal ecosystems to develop specific adaptation measures and coastal protection...

  8. Recommendations for Making Anti-Poaching Programs More Effective in the Southern African Region through the Analysis of Key Variables Impacting Upon the Poaching of Elephants in Botswana

    Science.gov (United States)

    2012-06-08

    Conference on Environment and Development (UNCED) that was held in Rio de Janeiro from 3-14 June 1992 concentrated on the state of the global environment...creeks and rivers . Deep sands characterize some other parts of this region. Northern Botswana experiences annual heavy rainfalls and as such, it is...low plains, creeks and rivers characterize Northeastern Botswana. During rainy seasons, the plains are usually muddy. The creeks and rivers constantly

  9. Catchment source contributions to the sediment-bound organic matter degrading salmonid spawning gravels in a lowland river, southern England

    Energy Technology Data Exchange (ETDEWEB)

    Collins, A.L., E-mail: adrian.collins@adas.co.uk [ADAS, Pendeford House, Wobaston Road, Wolverhampton WV9 5AP (United Kingdom); Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Williams, L.J.; Zhang, Y.S. [ADAS, Pendeford House, Wobaston Road, Wolverhampton WV9 5AP (United Kingdom); Marius, M. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Dungait, J.A.J. [Department of Sustainable Systems and Grassland Science, Rothamsted Research—North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Smallman, D.J. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Dixon, E.R. [Department of Sustainable Systems and Grassland Science, Rothamsted Research—North Wyke, Okehampton, Devon EX20 2SB (United Kingdom); Stringfellow, A. [Civil Engineering and Environment, University of Southampton, Highfield, Southampton S017 1BJ (United Kingdom); Sear, D.A. [Geography and Environment, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Jones, J.I. [School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom); Naden, P.S. [CEH Wallingford, Maclean Building, Benson Lane, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BB (United Kingdom)

    2013-07-01

    The ingress of particulate material into freshwater spawning substrates is thought to be contributing to the declining success of salmonids reported over recent years for many rivers. Accordingly, the need for reliable information on the key sources of the sediment problem has progressed up the management agenda. Whilst previous work has focussed on apportioning the sources of minerogenic fine sediment degrading spawning habitats, there remains a need to develop procedures for generating corresponding information for the potentially harmful sediment-bound organic matter that represents an overlooked component of interstitial sediment. A source tracing procedure based on composite signatures combining bulk stable {sup 13}C and {sup 15}N isotope values with organic molecular structures detected using near infrared (NIR) reflectance spectroscopy was therefore used to assess the primary sources of sediment-bound organic matter sampled from artificial spawning redds. Composite signatures were selected using a combination of the Kruskal–Wallis H-test, principal component analysis and GA-driven discriminant function analysis. Interstitial sediment samples were collected using time-integrating basket traps which were inserted at the start of the salmonid spawning season and extracted in conjunction with critical phases of fish development (eyeing, hatch, emergence, late spawning). Over the duration of these four basket extractions, the overall relative frequency-weighted average median (± 95% confidence limits) source contributions to the interstitial sediment-bound organic matter were estimated to be in the order: instream decaying vegetation (39 ± < 1%; full range 0–77%); damaged road verges (28 ± < 1%; full range 0–77%); septic tanks (22 ± < 1%; full range 0–50%), and; farm yard manures/slurries (11 ± < 1%; full range 0–61%). The reported procedure provides a promising basis for understanding the key sources of interstitial sediment-bound organic matter

  10. Assessment of regional air quality resulting from emission control in the Pearl River Delta region, southern China.

    Science.gov (United States)

    Wang, N; Lyu, X P; Deng, X J; Guo, H; Deng, T; Li, Y; Yin, C Q; Li, F; Wang, S Q

    2016-12-15

    To evaluate the impact of emission control measures on the air quality in the Pearl River Delta (PRD) region of South China, statistic data including atmospheric observations, emissions and energy consumptions during 2006-2014 were analyzed, and a Weather Research and Forecasting - Community Multi-scale Air Quality (WRF-CMAQ) model was used for various scenario simulations. Although energy consumption doubled from 2004 to 2014 and vehicle number significantly increased from 2006 to 2014, ambient SO 2 , NO 2 and PM 10 were reduced by 66%, 20% and 24%, respectively, mainly due to emissions control efforts. In contrast, O 3 increased by 19%. Model simulations of three emission control scenarios, including a baseline (a case in 2010), a CAP (a case in 2020 assuming control strength followed past control tendency) and a REF (a case in 2020 referring to the strict control measures based on recent policy/plans) were conducted to investigate the variations of air pollutants to the changes in NO x , VOCs and NH 3 emissions. Although the area mean concentrations of NO x , nitrate and PM 2.5 decreased under both NO x CAP (reduced by 1.8%, 0.7% and 0.2%, respectively) and NO x REF (reduced by 7.2%, 1.8% and 0.3%, respectively), a rising of PM 2.5 was found in certain areas as reducing NO x emissions elevated the atmospheric oxidizability. Furthermore, scenarios with NH 3 emission reductions showed that nitrate was sensitive to NH 3 emissions, with decreasing percentages of 0-10.6% and 0-48% under CAP and REF, respectively. Controlling emissions of VOCs reduced PM 2.5 in the southwestern PRD where severe photochemical pollution frequently occurred. It was also found that O 3 formation in PRD was generally VOCs-limited while turned to be NO x -limited in the afternoon (13:00-17:00), suggesting that cutting VOCs emissions would reduce the overall O 3 concentrations while mitigating NO x emissions in the afternoon could reduce the peak O 3 levels. Copyright © 2016 Elsevier B

  11. Early Pliocene Hiatus in Sand Output by the Colorado River: Evidence From Marine Deposits in the Salton Trough, Southern California

    Science.gov (United States)

    Dorsey, R. J.; Bykerk-Kauffman, A.

    2015-12-01

    Early Pliocene deposits in the western Salton Trough preserve a high-fidelity record of sediment dispersal into the marine realm during initiation and early evolution of the Colorado River (CR). Grain-size fractionation, sediment routing, and transport dynamics of the early CR delta are recorded in sediments of the Fish Creek - Vallecito basin, which was located ~100 km south of Yuma along the transform plate boundary at 5 Ma. Early Pliocene delivery of CR sand to the basin took place in two distinct pulses: (1) deposition of sandy turbidites (Wind Caves Mbr of the Latrania Fm) in a restricted submarine canyon at Split Mt Gorge between ~5.3 and 5.1 Ma; and (2) progradation of a thick, widespread, coarsening-up deltaic sequence of marine mudstone, sandstone, and coquinas (Deguynos Fm) between ~4.8 and 4.2 Ma. Estimated flux of CR sediment during Wind Caves deposition was weak (~3-5 Mt/yr) compared to the long-term average (172±64 Mt/yr). The two pulses of CR sand input are separated by the Coyote Clay (CC, ~5.1-4.8 Ma), a regionally correlable, greenish-yellow-weathering marine claystone unit at the base of the Deguynos Fm. CC gradationally overlies Wind Caves turbidites in the area of the paleocanyon. In contrast, in the Coyote Mts 15-23 km to the south and SE, CC rests on coarse-grained locally-derived late Miocene sedimentary rocks, Alverson volcanics, and metamorphic basement rock along a regional unconformity. Identical claystone facies occur in the NW Indio Hills (restores to Yuma at the mouth of the CR at 5 Ma), and Sierra Cucapa in Mexico (~200 km south of Yuma at 5 Ma). Marine localities outside of the Wind Caves paleocanyon experienced slow to negligible sedimentation along a rugged rocky shoreline until abrupt arrival of CR-derived clay. CC accumulated in a sand-starved, pro-delta marine setting (Winker, 1987) over an inferred N-S distance of ~200 km. We therefore reject an alternate hypothesis that CC accumulated on the muddy slope of the prograding CR

  12. A Measurement Invariance Examination of the Revised Child Anxiety and Depression Scale in a Southern Sample: Differential Item Functioning between African American and Caucasian Youth

    Science.gov (United States)

    Trent, Lindsay Rae; Buchanan, Erin; Ebesutani, Chad; Ale, Chelsea M.; Heiden, Laurie; Hight, Terry L.; Damon, John D.; Young, John

    2013-01-01

    This study examined the psychometric properties of the Revised Child Anxiety and Depression Scale in a large sample of youth from the Southern United States. The authors aimed to determine (a) if the established six-factor Revised Child Anxiety and Depression Scale structure could be replicated in this Southern sample and (b) if scores were…

  13. Comparison of groundwater quality from forested (Waimarino River), urban (Turangi), and natural wetland (South Taupo Wetlands) subcatchments at the southern end of Lake Taupo

    International Nuclear Information System (INIS)

    Rosen, M.R.; Reeves, R.R.; Eser, P.; Chague-Goff, C.; Coshell, L.

    1998-01-01

    Comparison of groundwater quality of three different land uses, (1) exotic pine plantation ready for harvest (Waimarino River Catchment), (2) an urban area characterised by a land treatment facility for sewage effluent from Turangi (Turangi oxidation ponds), and (3) a natural wetland (South Taupo Wetlands) demonstrates that groundwater quality in the southern region of the Lake Taupo catchment is controlled by both natural and human influences in the area. Comparative water quality issues can be summarised as follows. (1) Naturally high concentrations of reduced iron and manganese are present in all three study areas, with the highest concentrations found in the natural wetland area and around the Turangi land treatment facility. (2) Concentrations of sodium, chloride, potassium, and ammonium in the groundwater down-gradient of the Turangi oxidation ponds are elevated relative to the other two study areas. Stable isotopic signatures also show that the groundwater has been influenced by surface water from the oxidation ponds, mostly due to additional evaporation caused by the relatively long residence time of the water (125 days) in the oxidation ponds. Elevated concentrations of ammonium also occur in deep groundwater under the forest areas of the Waimarino River catchment. (3) The water at all three sites is generally unsuitable for drinking supplies due to naturally elevated concentrations of reduced iron and manganese in the groundwater and elevated concentrations of ammonium at many monitoring sites, particularly around the Turangi land treatment site and the Waimarino deep aquifer monitoring sites. Aeration followed by settling or filtration of the groundwater could significantly reduce the concentrations of iron and manganese. (4) Elevated concentrations of reduced iron and manganese are unlikely to affect the water quality of Lake Taupo as all reduced iron and manganese will be oxidised once the water reaches the lake and precipitate as oxyhydroxide minerals

  14. Soft sediment deformation associated with the East Patna Fault south of the Ganga River, northern India: Influence of the Himalayan tectonics on the southern Ganga plain

    Science.gov (United States)

    Verma, Aditya K.; Pati, Pitambar; Sharma, Vijay

    2017-08-01

    The geomorphic, tectonic and seismic aspects of the Ganga plain have been studied by several workers in the recent decades. However, the northern part of this tectonically active plain has been the prime focus in most of the studies. The region to the south of the Ganga River requires necessary attention, especially, regarding the seismic activities. The region lying immediately south of the Outer Himalayas (i.e. the Ganga plain) responds to the stress regime of the Himalayan Frontal Thrust Zone by movement along the existing basement faults (extending from the Indian Peninsula) and creating new surface faults within the sediment cover as well. As a result, several earthquakes have been recorded along these basement faults, such as the great earthquakes of 1934 and 1988 associated with the East Patna Fault. Large zones of ground failure and liquefaction in north Bihar (close to the Himalayan front), have been recorded associated with these earthquakes. The present study reports the soft sediment deformation structures from the south Bihar associated with the prehistoric earthquakes near the East Patna Fault for the first time. The seismites have been observed in the riverine sand bed of the Dardha River close to the East Patna Fault. Several types of liquefaction-induced deformation structures such as pillar and pocket structure, thixotropic wedge, liquefaction cusps and other water escape structures have been identified. The location of the observed seismites within the deformed zone of the East Patna Fault clearly indicates their formation due to activities along this fault. However, the distance of the liquefaction site from the recorded epicenters suggests its dissociation with the recorded earthquakes so far and hence possibly relates to any prehistoric seismic event. The occurrence of the earthquakes of a magnitude capable of forming liquefaction structure in the southern Ganga plain indicates the transfer of stress regime far from the Himalayan front into

  15. Current levels and composition profiles of PBDEs and alternative flame retardants in surface sediments from the Pearl River Delta, southern China: Comparison with historical data

    International Nuclear Information System (INIS)

    Chen, She-Jun; Feng, An-Hong; He, Ming-Jing; Chen, Man-Ying; Luo, Xiao-Jun; Mai, Bi-Xian

    2013-01-01

    Polybrominated diphenyl ethers (PBDEs) and alternative flame retardants were measured in surface sediments collected during 2009–2010 from the Pearl River Delta, southern China (a large manufacturing base for electronics/electrical products), to evaluate the influence of China's RoHS directive (adopted in 2006) on their environmental occurrence. The concentrations in sediments from different water systems ranged from 3.67 to 2520 ng/g (average of 17.1–588 ng/g) for PBDEs and from 0.22 to 5270 ng/g (average of 11.3–454 ng/g) for the alternative retardants. Although the PBDE levels have decreased significantly compared with those in sediments collected in 2002 in this region, the levels of alternative decabromodiphenyl ethane (DBDPE) have exceeded those of BDE209 (two predominant halogenated flame retardants (HFRs) in China) in the majority of sediments. This finding suggests a different contaminant pattern of HFRs in current sediments due to the replacement of the deca-BDE mixture with DBDPE in this region. In addition, sediment concentrations of discontinued PBDEs in the rural area are clearly elevated due to e-waste dismantling. The congener profiles of PBDEs in the current sediments (with more abundant lower-brominated congeners) differed substantially from those in 2002 and from the technical products, suggesting that biological or photolytic debromination of PBDEs may have occurred in the environment. - Highlights: ► PBDE levels in sediments have decreased substantially since China's RoHS directive. ► Contamination of novel DBDPE has exceeded that of deca-BDE in the PRD sediments. ► The congener profiles of PBDEs in the sediments have changed significantly. ► Significant biological or photolytic degradation of PBDEs may occur in the environment

  16. Relative growth in the fiddler crab Uca uruguayensis Nobili, 1901 (Brachyura, Ocypodidae from Garças River mangrove, Guaratuba Bay, southern Brazil

    Directory of Open Access Journals (Sweden)

    Salise Brandt Martins

    Full Text Available A study on the relative growth was carried out in a population of the fiddler crab Uca uruguayensis from the mangrove of Garças River, Guaratuba Bay, Paraná State, southern Brazil. The dimensions analyzed were the length of the major chela (LMC of males and width of the abdomen (AW of females, because they are related to reproductive activities of waving (males and egg incubation (females. The cheliped handedness in males was also analyzed. The LMC was measured in 480 males, the AW in 566 females, and all crabs had the carapace width (CW measured that was considered as the reference dimension for both sexes. The inflection point in the graphs between each the dimensions and CW was calculated with the aid of the software REGRANS. The CW ranged from 2.33 to 8.33 mm in males and from 1.65 to 7.79 mm in females. The relationship between CW and LMC showed an inflection point at 4.14 mm CW among males, and between CW and AW at 3.52 mm CW among females. The allometric growth was positive for both dimensions throughout the entire ontogeny of both sexes, before and after the puberty. The equations describing the relationship between CW and LMC in males were: logLMC = - 0.695960 + 1.72.logCW for juveniles and logLMC = - 1.212513 + 2.5.logCW for adults. In females, the equations were logAW = - 0.519071 + 1.02.logCW and logAW = - 0.902874 + 1.73.logCW, respectively for juveniles and adults. The population of U. uruguayensis from Guaratuba Bay is composed of the smallest crabs, and it also attains morphological sexual maturity at smallest CW. The frequency of occurrence of right and left handed males was statistically the same (1:1 as in most population of fiddler crabs.

  17. Seasonal and Spatial Variations of Macro Benthos in the Intertidal Mudflat of Southern Yellow River Delta, China in 2007/2008

    Science.gov (United States)

    Zou, Li; Yao, Xiao; Yamaguchi, Hitomi; Guo, Xinyu; Gao, Huiwang; Wang, Kai; Sun, Mingyi

    2018-04-01

    In order to examine the seasonal and spatial distributions of benthic animals in the intertidal mudflat of the southern Yellow River Delta, field investigations were carried out in 2007 and 2008 and multiple methods were applied. Results showed that, the biomass of macro benthos ranged at 0.75-1151.00 g wet m-2 and averaged at 156.31 g wet m-2, in which Mactra veneriformis accounted for 75.6%-93.4% of the total macro benthic biomass. More than 90% of macro benthos inhabited in the middle and low tide lines, and higher biomass occurred in early summer and lower in winter. Statistical analysis showed that: 1) M. veneriformis growth was primarily favored at higher temperature and lower salinity; 2) after long time interaction, benthic bivalve grazers led to patching distributions of Chlorophyll a (Chl a); 3) macro benthic biomass positively related with Chl a when the concentration of Chl a was low, but they were negatively related when Chl a concentration was high; and 4) furthermore, the biomass of benthic bivalves peaked in the sediment with median grain size about 0.55 mm, but decreased gradually in coarse or fine sediments. The secondary productivity ranged at 0.37-283.68 g m-2yr-1 and averaged at 47.88 g m-2 yr-1, in which 69.7% was contributed by M. veneriformis It was estimated that primary production was transformed to secondary production at a rate of 6.87% approximately, which implies that there is a local sustainability of high bivalve production.

  18. Development of a high-resolution binational vegetation map of the Santa Cruz River riparian corridor and surrounding watershed, southern Arizona and northern Sonora, Mexico

    Science.gov (United States)

    Wallace, Cynthia S.A.; Villarreal, Miguel L.; Norman, Laura M.

    2011-01-01

    This report summarizes the development of a binational vegetation map developed for the Santa Cruz Watershed, which straddles the southern border of Arizona and the northern border of Sonora, Mexico. The map was created as an environmental input to the Santa Cruz Watershed Ecosystem Portfolio Model (SCWEPM) that is being created by the U.S. Geological Survey for the watershed. The SCWEPM is a map-based multicriteria evaluation tool that allows stakeholders to explore tradeoffs between valued ecosystem services at multiple scales within a participatory decision-making process. Maps related to vegetation type and are needed for use in modeling wildlife habitat and other ecosystem services. Although detailed vegetation maps existed for the U.S. side of the border, there was a lack of consistent data for the Santa Cruz Watershed in Mexico. We produced a binational vegetation classification of the Santa Cruz River riparian habitat and watershed vegetation based on NatureServe Terrestrial Ecological Systems (TES) units using Classification And Regression Tree (CART) modeling. Environmental layers used as predictor data were derived from a seasonal set of Landsat Thematic Mapper (TM) images (spring, summer, and fall) and from a 30-meter digital-elevation-model (DEM) grid. Because both sources of environmental data are seamless across the international border, they are particularly suited to this binational modeling effort. Training data were compiled from existing field data for the riparian corridor and data collected by the NM-GAP (New Mexico Gap Analysis Project) team for the original Southwest Regional Gap Analysis Project (SWReGAP) modeling effort. Additional training data were collected from core areas of the SWReGAP classification itself, allowing the extrapolation of the SWReGAP mapping into the Mexican portion of the watershed without collecting additional training data.

  19. Comparing the urbanization and global warming impacts on extreme rainfall characteristics in Southern China Pearl River Delta megacity based on dynamical downscaling

    Science.gov (United States)

    Fung, K. Y.; Tam, C. Y.; Wang, Z.

    2017-12-01

    It is well known that urban land use can significantly influence the local temperature, precipitation and meteorology through altering land-atmosphere exchange of momentum, moisture and heat in urban areas. In recent decades, there has been a substantial increase ( 5-10%) on the intensity of extreme rainfall over Southeast China; it is projected to increase further according to the latest IPCC reports. In this study, we assess how urbanization and global warming together might impact on heavy precipitation characteristics over the highly urbanized Pearl River Delta (PRD) megacity, located in southern China. This is done by dynamically downscaling GFDL-ESM2M simulations for the present and future (RCP8.5) climate scenarios, using the Weather Research and Forecasting (WRF) model coupled with a single-layer urban canopy model (UCM). Over the PRD area, the WRF model is integrated at a resolution of 2km x 2km. To focus on extreme events, episodes covering daily rainfall intensity above the 99th percentile in Southeast China in the GFDL-ESM2M daily precipitation datasets were first identified. These extreme episodes were then dynamically downscaled in two parallel experiments with the following model designs: one with anthropogenic heat flux (AH) = 0 Wm-2 and the other with peak AH = 300 Wm-2 in the AH diurnal cycle over the urban domain. Results show that, with AH in urban area, the urban 2m-temperature can rise by about 2oC. This in turn leads to an increase of the mean as well as the extreme rain rates by 10-15% in urban domain. The latter is comparable to the impact of global warming alone, according to downscaling experiments for the RCP8.5 scenario. Implications of our results on urban effects on extreme rainfall under a warming background climate will be discussed.

  20. Patterning and predicting aquatic insect richness in four West-African coastal rivers using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Edia E.O.

    2010-10-01

    Full Text Available Despite their importance in stream management, the aquatic insect assemblages are still little known in West Africa. This is particularly true in South-Eastern Ivory Coast, where aquatic insect assemblages were hardly studied. We therefore aimed at characterising aquatic insect assemblages on four coastal rivers in South-Eastern Ivory Coast. Patterning aquatic insect assemblages was achieved using a Self-Organizing Map (SOM, an unsupervised Artificial Neural Networks (ANN method. This method was applied to pattern the samples based on the richness of five major orders of aquatic insects (Diptera, Ephemeroptera, Coleoptera, Trichoptera and Odonata. This permitted to identify three clusters that were mainly related to the local environmental status of sampling sites. Then, we used the environmental characteristics of the sites to predict, using a multilayer perceptron neural network (MLP, trained by BackPropagation algorithm (BP, a supervised ANN, the richness of the five insect orders. The BP showed high predictability (0.90 for both Diptera and Trichoptera, 0.84 for both Coleoptera and Odonata, 0.69 for Ephemeroptera. The most contributing variables in predicting the five insect order richness were pH, conductivity, total dissolved solids, water temperature, percentage of rock and the canopy. This underlines the crucial influence of both instream characteristics and riparian context.

  1. Hydrogeochemical characterization of the phreatic system of the coastal wetland located between Fiumi Uniti and Bevano rivers in the southern Po plain (Northern Italy).

    Science.gov (United States)

    Marconi, V.; Dinelli, E.; Antonellini, M.; Capaccioni, B.; Balugani, E.; Gabbianelli, G.

    2009-04-01

    A hydrogeochemical study has been undertaken on the phreatic system of the coastal area included between Fiumi Uniti and Bevano rivers (in the southern part of the Po plain, near the city of Ravenna) within the framework of the CIRCLE-ERANET project WATERKNOW on the effects of climate change on the mediterranean catchments. It is one of the first attempt in the area to characterize the shallow groundwater water system and to investigate if the arsenic anomaly, known in deeper groundwater (about 100 µg/l according to recent Annual Groundwater Quality Reports of Emilia-Romagna Region), occurs also in the phreatic system. The coastal part of the Po plain consists of a low-lying and mechanically-drained farmland further from the sea and of a narrow belt of dunes and pine forests in the backshore area. The study area is recognized as a protected area at european (ZPS and SIC, site code number: IT 14070009), national and regional level (Po delta Park area). As a result of an intensive exploitation of coastal aquifers for agricultural, industrial, and civil uses, both the phreatic aquifer and the surface waters (drainage ditches and ponds) have been contaminated by seawater and by deeper groundwater. Samples representative of the top of the water table were collected in Summer 2008 in 22 auger-holes and in 3 shallow piezometers (6 m deep) documenting the deeper layers of the phreatic groundwater system. Temperature, electrical conductivity, pH and Eh of the groundwater and of the surface water were measured on site using portable instruments. Samples were filtered directly in the field, an aliquot was acidified with diluted HCl for metal analysis. Cations were determined by Flame Atomic Absorption (thermo S-series spectrometer), anions by ion chromatography (Dionex ICS-90), Fe, As, Si, B by ICP-OES (Thermo iCAP6000). The data collected in the field show that a fresh groundwater lens is still present at the top of the phreatic aquifer in the backshore area and that the

  2. A comparative analysis of restoration measures and their effects on hydromorphology and benthic invertebrates in 26 central and southern European rivers.

    NARCIS (Netherlands)

    Jähnig, S.C.; Brabec, K.; Buffagni, A.; Erba, S.; Lorenz, A.; Ofenböck, T.; Verdonschot, P.F.M.; Hering, D.

    2010-01-01

    1. Hydromorphological river restoration usually leads to habitat diversification, but the effects on benthic invertebrates, which are frequently used to assess river ecological status, are minor. We compared the effects of river restoration on morphology and benthic invertebrates by investigating 26

  3. Precipitation in Santa Barbara, CA on varying timescales and the relationships with the El Niño Southern Oscillation, the Madden-Julian Oscillation, and atmospheric rivers

    Science.gov (United States)

    Harris, S. M.; Carvalho, L. V.; Jones, C.

    2013-12-01

    This study aimed to understand the patterns and variations of extreme precipitation events that occur in Santa Barbara County and determine the relationships with various phenomena that affect the region. Santa Barbara, CA is an area with complex topography that is disposed to numerous hazard events including landslides and flooding, particularly during the region's rainy season (Nov.-Apr.). These incidents are especially frequent in the seasons after fire-events, another hazard common to the region. In addition, Santa Barbara is affected by several tropical phenomena that influence precipitation on varying timescales including the El Niño Southern Oscillation (ENSO), the Madden-Julian Oscillation (MJO), and atmospheric rivers (ARs). It is well known that ENSO and the MJO influence storms that occur in southern California through processes such as the modulation of the upper level jet and the low level moisture flux. ARs have been revealed to be responsible for the movement of large quantities of water vapor from tropical areas to the midlatitudes and have been linked to high-intensity storms throughout the western coast of North America. We examined rainy season (Nov.-Apr.) precipitation within Santa Barbara County using hourly rainfall data spanning approximately forty years (~1971-2010) from seven, local, rain gauge stations. The distributions as well as totals of precipitation on varying timescales (hourly, daily, seasonal, and yearly) were defined for specified intensities of rainfall based upon the 75th, 90th, 95th, and 99th percentiles. Persistence, expressed as the number of consecutive hours (or days) including intense precipitation defined according to the percentiles, was investigated on the hourly and daily timescales. In addition, specified storm episodes identified in this study were examined with data from the Tropical Rainfall Measurement Mission in order to assess the spatial features of high-intensity storms. Results from this analysis will be

  4. Selecting Communication Channels for Substance Misuse Prevention with At-Risk African-American Emerging Adults Living in the Southern United States

    Science.gov (United States)

    Tucker, Jalie A.; Cheong, JeeWon; Chandler, Susan D.

    2016-01-01

    Natural health information sources used by African-American emerging adults were investigated to identify sources associated with high and low substance-related risk. Participants (110 males, 234 females; M age = 18.9 years) were recruited using respondent-driven sampling, and structured interviews assessed substance use, sources of health…

  5. Sources and distribution of allochthonous organic matter in surface sediment from the Seomjin River to the southern inner shelf of Korea

    Science.gov (United States)

    Badejo, Adegoke Olugboyega; Hyun, Sangmin; Kim, Wonnyon; Ju, Se-Jong; Song, Bareum

    2017-12-01

    The spatial distributions of δ13C, δ15N, and n-alkanes were investigated to determine the source and transportation of allochthonous organic matter from the mouth of the Seomjin River to the southern inner shelf break of Korea. Total organic carbon (%) ranged from 0.3% to 1.6% (average = 0.80%, n = 81), and the C/N ratio varied from 2.4 to 12.4 (average = 6.76, n = 81). The δ13C values ranged from -25.86 to -20.26‰ (average = -21.47‰, n = 81), and δ15N values ranged from 4.37‰ to 8.57‰ (average = 6.72‰, n = 81). The contribution of the terrestrial fraction of organic matter to the total ranged from 4.4% to 97.7% (average = 24.4%, n = 81), suggesting higher amounts around the catchment area and lower amounts in the offshore area. The concentration of total n-alkanes ( nC25 - nC35) was higher at the boundary between the outer bay and inner shelf break (BOBIS). Average chain length and the carbon preference index both indicated that major leaf wax n-alkanes accounted for the observed distribution of terrestrial organic matter, and were dominant in the inner shelf break (around BOBIS) and outer shelf break. Based on the spatial distribution of the total n-alkanes and the sum of nC27, nC29, and nC31, the terrestrial organic matter distribution was considered to be controlled by local oceanographic conditions, especially at the center of the BOBIS. In addition to enabling the distribution and source of terrestrial organic matter to be identified, the n-alkanes indicated that minor anthropogenic allochthonous organic materials were superimposed on the total organic materials in the central part of Yeosu Bay and the catchment area. The n-alkane indices revealed weathered petroleum contamination, with contamination levels being relatively low at the present time.

  6. African Journals Online: Browse Alphabetically -- letter S

    African Journals Online (AJOL)

    Items 51 - 62 of 62 ... The Southern African Journal of HIV Medicine is a medical journal focused on HIV/AIDS treatment, prevention and related topics relevant to clinical and public health practice. The purpose of ... Southern Forests: a Journal of Forest Science is one of the leading forestry journals in the Southern Hemisphere.

  7. Compulsory African languages in tertiary education: prejudices from ...

    African Journals Online (AJOL)

    Southern African Linguistics and Applied Language Studies ... of African languages, in reality more has to be done if policy provisions are to be realised. ... of language attitude planning and that existing resources at universities should be ...

  8. Medical ethics education: thoughts on a South African medical ...

    African Journals Online (AJOL)

    South African Journal of Higher Education ... emphasised the place of bioethics within the emerging integrated medical curricula in southern Africa. ... There has been little development of African syllabi in bioethics that reflect the plasticity of ...

  9. Determining the appropriate code in a South African business ...

    African Journals Online (AJOL)

    Determining the appropriate code in a South African business environment. ... Southern African Linguistics and Applied Language Studies ... would be perceived to enhance the quality of the interaction between client and service provider.

  10. African Journals Online: Swaziland

    African Journals Online (AJOL)

    The journal publishes research papers, case studies, essays and review articles as well as first hand experiences in soil, plant, water and animal sciences, natural resources management, home economics and nutrition, and other related areas of relevance to the Southern African Development Community (SADC) region in ...

  11. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Continuing Medical Education; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African Business Review; The Basis of Distinction Between Qualitative and Quantitative Research in Social Science: Reflection on ...

  12. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Southern African Business Review; Effect of Globalization on Sovereignty of States Nnamdi Azikiwe University Journal of International Law and Jurisprudence; The Influence of Motivation on Employees' Performance: A Study of Some Selected Firms in Anambra State AFRREV IJAH: An International Journal of Arts and ...

  13. African Journals Online (AJOL)

    African Journals Online (AJOL)

    More about AJOL and the challenges we work to address. AJOL hosts ... Southern African Business Review; Income Tax Assignment under the Ethiopian Constitution: Issues to Worry About Mizan Law ... AFRREV IJAH: An International Journal of Arts and Humanities; Effect of Globalization on Sovereignty of States Nnamdi ...

  14. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Southern African Business Review; The Roles of Information Communication Technologies in Education: Review Article with Emphasis to the Computer and ... AFRREV IJAH: An International Journal of Arts and Humanities; Book Review: Insurance in Ethiopia: Historical Development, Present Status and Future Challenges

  15. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Ethiopian Journal of Education and Sciences; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African Business Review; Income Tax Assignment under the Ethiopian Constitution: Issues to Worry About Mizan Law ...

  16. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Shakespeare in Southern Africa. Vol 28, No 1 (2018). Ethiopian Journal of Agricultural Sciences. Vol 15, No 1 (2018). SAHARA-J: Journal of Social Aspects of HIV/AIDS. Vol 20, No 10 (2017). Nigerian Journal of Clinical Practice. Vol 108, No 2 (2018). South African Medical Journal. Vol 21, No 1 (2018). Nigerian Journal of ...

  17. Changing styles of crustal growth in Southern Africa: constraints from geochemical and Sr-Nd isotope studies in Archaean to Pan African terrains

    International Nuclear Information System (INIS)

    McDermott, F.; Hawkesworth, C.J.; Harris, N.B.W.

    1988-01-01

    Nd isotopic data was presented for southern Africa in support of episodic crustal growth. Over 50 percent of the continental crust there had formed before 2.5 Ga, and less than 10 percent was produced after about 1.0 Ga. The data imply a mean crustal age of about 2.4 Ga for southern Africa, and a higher rate of crustal growth than that derived from Australian shale data, particularly during the Proterozoic. Isotopic data from Damara metasediments imply that there is no need to invoke decoupling of the Rb-Sr and Sm-Nd systems in the continental crust

  18. Changing styles of crustal growth in Southern Africa: Constraints from geochemical and Sr-Nd isotope studies in Archaean to Pan African terrains

    Science.gov (United States)

    Mcdermott, F.; Hawkesworth, C. J.; Harris, N. B. W.

    1988-01-01

    Nd isotopic data was presented for southern Africa in support of episodic crustal growth. Over 50 percent of the continental crust there had formed before 2.5 Ga, and less than 10 percent was produced after about 1.0 Ga. The data imply a mean crustal age of about 2.4 Ga for southern Africa, and a higher rate of crustal growth than that derived from Australian shale data, particularly during the Proterozoic. Isotopic data from Damara metasediments imply that there is no need to invoke decoupling of the Rb-Sr and Sm-Nd systems in the continental crust.

  19. The upper reaches of the largest river in Southern China as an “evolutionary front” of tropical plants: Evidences from Asia-endemic genus Hiptage (Malpighiaceae

    Directory of Open Access Journals (Sweden)

    Ren, M. X.

    2015-12-01

    Full Text Available The biodiversity hotspot at the Guizhou–Yunnan–Guangxi borders is a distribution centre of tropical plants in China. It spans the whole upper reaches of Zhujiang River, the largest river in Southern China. In this paper, I aimed to explore the roles of the river in the spread and diversification of tropical plants in this area, using the Asia-endemic genus Hiptage Gaertn. (Malpighiaceae as an example. Two diversity and endemism centres of Hiptage are recognized: Indo-China Peninsula and upper reaches of Zhujiang River (UZJ. The area-adjusted endemism index further indicates UZJ as the most important distribution region of endemic species since UZJ has a very small area (~210,000 km2 but six out of the total seven species are narrow endemics. UZJ is located at the northern edge of distribution ranges of Hiptage, which resulted mainly from the north-west–south-east river systems of UZJ promoting northward spreads of this tropical genus. The highly-fragmented limestone landscapes in this region may promote habitat isolation and tends to be the main driving factor for origins of these endemic species. Hiptage is also distinctive for its highly-specialized pollination system, mirror-image flowers, which probably facilitates species diversification via floral and pollination isolation. Other studies also found UZJ as a major diversification centre of the tropical plant families Gesneriaceae and Begoniaceae. Thereafter, it is concluded that UZJ is an “evolutionary front” of tropical plants in China, which contributes significantly to the origin and maintenance of the unique biodiversity in the area.El hotspot de biodiversidad en las fronteras de las provincias Guizhou-Yunnan- Guangxi es un centro de distribución de plantas tropicales en China. Se extiende por toda la cuenca alta del río Zhujiang, el mayor río del sur de China. En este artículo, se explora el papel del río en la propagación y la diversificación de las plantas tropicales

  20. Empowering Women for Development through Community-Driven Sustainable Programmes: A Response to Traditional Patriarchal Power in the Southern African Region

    Science.gov (United States)

    Braimoh, Dele; Lekoko, Rebecca; Alade, Eunice B.

    2004-01-01

    In the Southern Africa region, the act of prejudice against women mostly occurs where patriarchal power reigns. This type of power is felt in areas such as inheritance right, division of labour, access to political and economic resources and legal and social matters. Other areas of discrimination against women include access to educational and…

  1. Livestock First Reached Southern Africa in Two Separate Events.

    Science.gov (United States)

    Sadr, Karim

    2015-01-01

    After several decades of research on the subject, we now know when the first livestock reached southern Africa but the question of how they got there remains a contentious topic. Debate centres on whether they were brought with a large migration of Khoe-speakers who originated from East Africa; or whether the livestock were traded down-the-line among hunter-gatherer communities; or indeed whether there was a long history of diverse small scale population movements in this part of the world, one or more of which 'infiltrated' livestock into southern Africa. A new analysis of the distribution of stone toolkits from a sizeable sample of sub-equatorial African Later Stone Age sites, coupled with existing knowledge of the distribution of the earliest livestock remains and ceramics vessels, has allowed us to isolate two separate infiltration events that brought the first livestock into southern Africa just over 2000 years ago; one infiltration was along the Atlantic seaboard and another entered the middle reaches of the Limpopo River Basin. These findings agree well with the latest results of genetic research which together indicate that multiple, small-scale infiltrations probably were responsible for bringing the first livestock into southern Africa.

  2. Model testing of radioactive contamination by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu of water and bottom sediments in the Techa River (Southern Urals, Russia)

    Energy Technology Data Exchange (ETDEWEB)

    Kryshev, I.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)], E-mail: ecomod@obninsk.com; Boyer, P.; Monte, L.; Brittain, J.E.; Dzyuba, N.N.; Krylov, A.L.; Kryshev, A.I.; Nosov, A.V.; Sanina, K.D.; Zheleznyak, M.I. [Scientific and Production Association ' Typhoon' , 82 Lenin Ave., Obninsk, Kaluga Region, 249038 (Russian Federation)

    2009-03-15

    This paper presents results of testing models for the radioactive contamination of river water and bottom sediments by {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu. The scenario for the model testing was based on data from the Techa River (Southern Urals, Russia), which was contaminated as a result of discharges of liquid radioactive waste into the river. The endpoints of the scenario were model predictions of the activity concentrations of {sup 90}Sr, {sup 137}Cs and {sup 239,240}Pu in water and bottom sediments along the Techa River in 1996. Calculations for the Techa scenario were performed by six participant teams from France (model CASTEAUR), Italy (model MARTE), Russia (models TRANSFER-2, CASSANDRA, GIDRO-W) and Ukraine (model RIVTOX), all using different models. As a whole, the radionuclide predictions for {sup 90}Sr in water for all considered models, {sup 137}Cs for MARTE and TRANSFER-2, and {sup 239,240}Pu for TRANSFER-2 and CASSANDRA can be considered sufficiently reliable, whereas the prediction for sediments should be considered cautiously. At the same time the CASTEAUR and RIVTOX models estimate the activity concentrations of {sup 137}Cs and {sup 239,240}Pu in water more reliably than in bottom sediments. The models MARTE ({sup 239,240}Pu) and CASSANDRA ({sup 137}Cs) evaluated the activity concentrations of radionuclides in sediments with about the same agreement with observations as for water. For {sup 90}Sr and {sup 137}Cs the agreement between empirical data and model predictions was good, but not for all the observations of {sup 239,240}Pu in the river water-bottom sediment system. The modelling of {sup 239,240}Pu distribution proved difficult because, in contrast to {sup 137}Cs and {sup 90}Sr, most of models have not been previously tested or validated for plutonium.

  3. Chronology of Miocene-Pliocene deposits at Split Mountain Gorge, Southern California: A record of regional tectonics and Colorado River evolution

    Science.gov (United States)

    Dorsey, R.J.; Fluette, A.; McDougall, K.; Housen, B.A.; Janecke, S.U.; Axen, G.J.; Shirvell, C.R.

    2007-01-01

    Late Miocene to early Pliocene deposit at Split Mountain Gorge, California, preserve a record of basinal response to changes in regional tectonics, paleogeography, and evolution of the Colorado River. The base of the Elephant Trees Formation, magnetostratigraphically dated as 8.1 ?? 0.4 Ma, provides the earliest well-dated record of extension in the southwestern Salton Trough. The oldest marine sediments are ca. 6.3 Ma. The nearly synchronous timing of marine incursion in the Salton Trough and northern Gulf of California region supports a model for localization of Pacific-North America plate motion in the Gulf ca. 6 Ma. The first appearance of Colorado River sand at the Miocene-Pliocene boundary (5.33 Ma) suggests rapid propagation of the river to the Salton Trough, and supports a lake-spillover hypothesis for initiation of the lower Colorado River. ?? 2007 Geological Society of America.

  4. First Hemolivia from southern Africa: reassigning chelonian ...

    African Journals Online (AJOL)

    To date, only a single species of Hemolivia, Hemolivia mauritanica (Sergent & Sergent, 1904), has been described from African terrestrial tortoises. Although various haemogregarines have been described from southern African terrapins and tortoises, including species from the genus Haemogregarina and one from the ...

  5. African Zoology - Vol 11, No 2 (1976)

    African Journals Online (AJOL)

    Patterns in the Distribution of Southern African Terrestrial Tortoises (Cryptodira: Testudinidae) · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. John Comrie Greig, Peter D. Burdett, 251-273 ...

  6. South African Antarctic earth science research programme

    CSIR Research Space (South Africa)

    SASCAR

    1984-02-01

    Full Text Available This document describes the past, current and planned future South African earth science research programme in the Antarctic, Southern Ocean and subantarctic regions. The scientific programme comprises five components into which present and future...

  7. Applications of multiple change point detections to monthly streamflow and rainfall in Xijiang River in southern China, part II: trend and mean

    Science.gov (United States)

    Chen, Yongqin David; Jiang, Jianmin; Zhu, Yuxiang; Huang, Changxing; Zhang, Qiang

    2018-05-01

    This article, as part II, illustrates applications of other two algorithms, i.e., the scanning F test of change points in trend and the scanning t test of change points in mean, to both series of the normalized streamflow index (NSI) at Makou section in the Xijiang River and the normalized precipitation index (NPI) over the watershed of Xijiang River. The results from these two tests show mainly positive coherency of changes between the NSI and NPI. However, some minor negative coherency patches may expose somewhat impacts of human activities, but they were often associated with nearly normal climate periods. These suggest that the runoff still depends upon well the precipitation in the Xijiang catchment. The anthropogenic disturbances have not yet reached up to violating natural relationship on the whole in this river.

  8. Identification and effects of anthropogenic emissions of U and Th on the composition of sediments in a river/estuarine system in Southern Spain

    International Nuclear Information System (INIS)

    Martinez-Aguirre, A.; Garcia-Leon, M.

    1994-01-01

    A study of the distribution of natural radionuclides in different fractions of river bottom sediments has been carried out. The study has shown that the majority of the total U in the sediment is located in the non-residual fraction of the sediment, while Th is more suitable to be present in the residual fraction of the sediments. Also, it has been found that coprecipitation with amorphous ferromanganese oxyhydroxides is the main process of incorporation of U- and Th-isotopes from the water column to suspended matter or bottom sediments. The distribution of the radionuclides and the analysis of some relevant activity ratios in different fractions of sediments has made an unequivocal connection between the enhanced U content in river sediments and the waste discharged into the Odiel and Tinto rivers by the operation in the vicinity of phosphate fertilizer industries. (Author)

  9. Impacts of climate change on water resources and hydropower systems in central and southern Africa

    Energy Technology Data Exchange (ETDEWEB)

    Hamududu, Byman H

    2012-11-15

    projected for a slight decrease (0.05%), Asia with an increase of 0.27%, Europe a reduction up to 0.16% while America is projected to have an increase of 0.05%. In the eastern African region, it was shown that hydropower production is likely to increase by 0.59%, the central with 0.22% and the western with a 0.03%. The southern, and northern African regions were projected to have reductions of 0.83% and 0.48% respectively. The basins with increases in flow projections have a slight increase on hydropower production but not proportional to the increase in precipitation. The basins with decreases had even high change as the reduction was further increased by evaporation losses. The hydropower production potential of most of southern African basins is likely to decrease in the future due to the impact of climate change while the central African region shows an increasing trend. The hydropower system in these regions will be affected consequently. The hydropower production changes will vary from basin to basin in these regions. The Zambezi, Kafue and Shire river basins have negative changes while the Congo, Kwanza and Kabompo river basins have positive changes. The hydropower production potential in the Zambezi basin decreases by 9 - 34%. The hydropower production potential in the Kafue basin decreases by 8 - 34% and the Shire basin decreases by 7 - 14 %. The southern region will become drier with shorter rainy seasons. The central region will become wetter with increased runoff. The hydropower production potential in the Congo basin reduces slightly and then increases by 4% by the end of the century. The hydropower production potential in the Kwanza basin decreases by 3% and then increases by 10% towards the end of the century and the Kabompo basin production increases by 6 - 18%. It can be concluded that in the central African region hydropower production will, in general, increase while the southern African region, hydropower production will decrease. In summary, the

  10. The Usumacinta-Grijalva beach-ridge plain in southern Mexico : A high-resolution archive of river discharge and precipitation

    NARCIS (Netherlands)

    Nooren, C.A.M.; Hoek, W.Z.; Winkels, T.G.; Huizinga, A.; van der Plicht, J.; Van Dam, R.; Van Heteren, S.; van Bergen, M.J.; Prins, M.A.; Reimann, T.; Wallinga, J.; Cohen, K.M.; Minderhoud, P.S.J.; Middelkoop, H.

    2017-01-01

    The beach-ridge sequence of the Usumacinta-Grijalva delta borders a 300 km long section of the southern Gulf of Mexico coast. With around 500 beach ridges formed in the last 6500 years, the sequence is unsurpassed in the world in terms of numbers of individual ridges preserved, continuity of the

  11. Examining the specific effects of context on adaptive behavior and achievement in a rural African community: six case studies from rural areas of Southern province, Zambia.

    Science.gov (United States)

    Tan, Mei; Reich, Jodi; Hart, Lesley; Thuma, Philip E; Grigorenko, Elena L

    2014-02-01

    Generally accepted as universal, the construct of adaptive behavior differs in its manifestations across different cultures and settings. The Vineland-II (Sparrow et al. in Vineland Adaptive Behavior Scales, Second edn. AGS Publishing, Circle Pines, MN, 2005) was translated into Chitonga and adapted to the setting of rural Southern Province, Zambia. This version was administered to the parents/caregivers of 114 children (grades 3-7, mean age = 12.94, SD = 2.34). The relationships between these children's adaptive behavior, academic achievement and cognitive ability indicators are compared to those usually observed in US samples. Results reflect no association between adaptive behavior and cognitive ability indicators, but a strong relationship between high adaptive behavior and reading-related measures. Six case studies of children with high and low scores on the Vineland-II are presented to illustrate the possible factors affecting these outcomes.

  12. PALEODRAINAGES OF THE EASTERN SAHARA - THE RADAR RIVERS REVISITED (SIR - A/B IMPLICATIONS FOR A MID - TERTIARY TRANS - AFRICAN DRAINAGE SYSTEM).

    Science.gov (United States)

    McCauley, John F.; Breed, Carlos S.; Schaber, Gerald G.; McHugh, William P.; Issawi, Bahay; Haynes, C. Vance; Grolier, Maurice J.; El Kilani, Ali

    1986-01-01

    A complex history of Cenozoic fluvial activity in the presently hyperarid eastern Sahara is inferred from Shuttle Imaging Radar (SIR) data and postflight field investigations in southwest Egypt and northwest Sudan. SIR images were coregistered with Landsat and existing maps as a guide to exploration of the buried paleodrainages (radar rivers) first discovered by SIR-A. Field observations explain the radar responses of three types of radar rivers: RR-1, RR-2, and RR-3. A generalized model of the radar rivers, based on field studies and regional geologic relations, shows apparent changes in river regimen since the large valleys were established during the late Paleogene-early Neogene eras. SIR-based mapping of these paleodrainages, although incomplete, reveals missing links in an area once thought to be devoid of master streams.

  13. The impact of Manjil and Tarik dams (Sefidroud River, southern Caspian Sea basin on morphological traits of Siah Mahi Capoeta gracilis (Pisces: Cyprinidae

    Directory of Open Access Journals (Sweden)

    Adeleh Heidari

    2013-08-01

    Full Text Available It has been postulated that the building of the Manjil and Tarik dams on Sefidroud River has led to the body shape variation of Capoeta gracilis in up- and downstream populations due to the isolation. In this study, Geometric morphometric approach was used to explore body shape variations of Capoeta gracilis populations in up- and downstream Manjil and Tarik dams in Sefidroud River from south of the Caspian Sea basin. The shape of 90 individuals from three sampling sites was extracted by recording the 2-D coordinates of 13 landmark points. PCA, CVA, DFA and CA analysis were used to examine shape differences among the populations. The significant differences were found among the shape of the populations and these differences were observed in the snout, the caudal peduncle and head. The present study indicated the body shape differences in the populations of Capoeta gracilis in the Sefidroud River across the Manjil and Tarik dams, probably due to the dam construction showing anthropogenic transformation of rivers influences body shape in an aquatic organism.

  14. Sediment Dynamics Affecting the Threatened Santa Ana Sucker in the Highly-modified Santa Ana River and Inset Channel, Southern California, USA

    Science.gov (United States)

    Minear, J. T.; Wright, S. A.

    2015-12-01

    In this study, we investigate the sediment dynamics of the low-flow channel of the Santa Ana River that is formed by wastewater discharges and contains some of the last remaining habitat of the Santa Ana Sucker (Catostomus santaanae). The Santa Ana River is a highly-modified river draining the San Bernardino Mountains and Inland Empire metropolitan area east of Los Angeles. Home to over 4 million people, the watershed provides habitat for the federally-threatened Santa Ana Sucker, which presently reside within the mainstem Santa Ana River in a reach supported by year-round constant discharges from water treatment plants. The nearly constant low-flow wastewater discharges and infrequent runoff events create a small, approximately 8 m wide, inset channel within the approximately 300 m wide mainstem channel that is typically dry except for large flood flows. The sediment dynamics within the inset channel are characterized by constantly evolving bed substrate and sediment transport rates, and occasional channel avulsions. The sediment dynamics have large influence on the Sucker, which rely on coarse-substrate (gravel and cobble) for their food production. In WY 2013 through the present, we investigated the sediment dynamics of the inset channel using repeat bathymetric and substrate surveys, bedload sampling, and discharge measurements. We found two distinct phases of the inset channel behavior: 1. 'Reset' flows, where sediment-laden mainstem discharges from upstream runoff events result in sand deposition in the inset channel or avulse the inset channel onto previously dry riverbed; and 2. 'Winnowing' flows, whereby the sand within the inset channel is removed by clear-water low flows from the wastewater treatment plant discharges. Thus, in contrast to many regulated rivers where high flows are required to flush fine sediments from the bed (for example, downstream from dams), in the Santa Ana River the low flows from wastewater treatment plants serve as the flushing

  15. Annual congress of the South African Society of Pathologists

    International Nuclear Information System (INIS)

    1981-01-01

    The joint annual congress of the South African Society of Pathologists, International Academy of Pathology, South African Association of Clinical Biochemists and the Southern African Microbiology Society, was held from 13 to 15 July 1981 in Bloemfontein. This congress covered facets of clinical biochemistry, anatomical pathology, virology, microbiology, immunology and molecular biology

  16. Tectonic evolution of the Pan-African arc assemblage in Southern Sinai An example from the Sa'al-Zaghra belt

    Science.gov (United States)

    Hassan, M.; Fowler, A.; Hassan, I.; Abu-Alam, T.; Stüwe, K.

    2012-04-01

    The southern Sinai basement is part of the broader Neoproterozoic Arabian-Nubian Shield, which occupies parts of northeastern Africa and the Arabian Peninsula. The Sinai exposures of the shield are uniquely located as they form a bridge between the two halves of the shield that are elsewhere separated by the Red Sea rift. For shield terrain fragments are exposed in Sinai: the Feiran-Solaf, Kid, Taba-Elat and Sa'al-Zaghra metamorphic belts. Of these, the Sa'al Zaghra terrain has received the least attention. The four terrains are separated from each other by vast areas of syn- and post tectonic granitoids that complicate the correlation and have led to numerous controversies with respect to their interpretation. In this project structural, petrological and age dating will be carried out to clarify the evolution of the Sa'al Zaghra terrain in order to establish the relationship between it and the other terrains. Preliminary work already undertaken during this research suggests that the Sa'al-Zaghra and Kid terrains have much in common with respect to their lithological assemblages, as well as their structural and metamorphic histories. The same may be said of the Feiran-Solaf and Taba-Elat terrains. Juxtaposition of these paired terrains presents an enigma in that the Sa'al-Zaghra and Kid terrains appear to separate the Feiran-Solaf and Taba-Elat terrains from each other. There are possibilities of ancient transform systems that may explain this configuration.

  17. River crossings by Ateles geoffroyi and Alouatta pigra in southern Mexico: A preliminary report Habilidad para cruzar ríos en Ateles geoffroyi y Alouatta pigra en el sur de México: Un reporte preliminar

    Directory of Open Access Journals (Sweden)

    ÓSCAR M CHAVES

    2010-01-01

    Full Text Available During a nine month field study, we assess the ability of spider (Ateles geoffroyi and howler (Alouatta pigra monkeys to cross a large Mesoamerican river, and if this behavior is related to deforestation and/or human population size on the disturbed riverbank. The study was conducted along the Lacantún River, southern Mexico, which .divides the Montes Azules Biosphere Reserve and the Marqués de Comillas disturbed region. We collected data on river crossings by both monkey species from 428 hours of surveys along the river and 58 questionnaires completed by knowledgeable local informants. Furthermore, we determined the frequency of river crossing by the two species, location and direction of river-crossing, bank-to-bank river width at the location of reported sighting, and the relationship with deforestation rates and/or human population size in the Marqués de Comillas region. We observed on two separate occasions spider monkeys crossing the river from the disturbed area to the reserve, but howler monkeys were never observed crossing. Interviews suggest, however, that howler monkeys cross the river more frequently than spider monkeys (13 versus 8 reports, respectively. We found that bank-to-bank river width was smaller at river crossing locations in each study site than along the river in general. Furthermore, we found no relationship between river crossings and some human pressures such as deforestation and population size in the region. Whatever the underlying pressures that drive river-crossing events in these two primate species in this region, they appear to be sufficiently strong to stimulate this behavior to occur from time to time.Durante nueve meses evaluamos si los monos araña (Ateles geoffroyi y los monos aulladores (Alouatta pigra tenían la capacidad para cruzar uno de los ríos más grandes de México, y si este comportamiento estaba relacionado con la deforestación y/o el tamaño de las poblaciones humanas en la margen alterada

  18. Quantification of climate and vegetation from southern African Middle Stone Age sites - an application using Late Pleistocene plant material from Sibudu, South Africa

    Science.gov (United States)

    Bruch, Angela A.; Sievers, Christine; Wadley, Lyn

    2012-06-01

    In southern Africa numerous Middle Stone Age (MSA) sites document important steps in technological and behavioural development leading to significant changes in the lifeways of modern humans. To assess whether these cultural changes and developments may be related to environmental changes we need to ascertain past environments. To do this we apply a new quantitative method, the GIS-based Coexistence Approach (CAGIS), on fossil plant material from the MSA site Sibudu, KwaZulu-Natal, South Africa. Previous qualitative environmental interpretations of the fossil fauna and flora of the site remain ambiguous. Because much of the material is anthropogenically introduced, it is difficult to distinguish between the effects of natural changes in the local vegetation and behavioural changes of the people that inhabited the shelter. CAGIS can be applied to such biased assemblages and seems to be an adequate method to directly quantify palaeoclimate and vegetation parameters at an archaeological site. The CAGIS analysis shows that during the Howiesons Poort (HP) Industry winters were slightly colder and drier than present, whereas during summer, temperatures and precipitation were similar to today. Post-HP winters were drier and colder than present, presumably colder than during the HP. Summer temperatures remained the same, but summer precipitation decreased from the HP to post-HP. Vegetation cover was less than today, may be even less than during the HP. The late MSA was observably warmer than the older periods, especially during winter. At the same time summer precipitation slightly increased and vegetation became more dense, but still remained generally open similar to today's anthropogenic landscape. Generally, climatic changes are most pronouncedly reflected in winter temperature parameters, especially in minimum winter temperatures, and to a lesser extent by changes in summer precipitation. The observed ecological trends seem to be affected mainly by variations through

  19. Range Analysis and Terrain Preference of Adult Southern White Rhinoceros (Ceratotherium simum in a South African Private Game Reserve: Insights into Carrying Capacity and Future Management.

    Directory of Open Access Journals (Sweden)

    S Thompson

    Full Text Available The Southern white rhinoceros (Ceratotherium simum is a threatened species, central to the tourism appeal of private game reserves in South Africa. Privately owned reserves in South Africa tend to be smaller than government run reserves such as Kruger National Park. Because of their relatively small size and the often heterogeneous nature of the landscape private game reserve managers benefit from detailed knowledge of white rhinoceros terrain selection preferences, which can be assessed from their ranging behaviours. We collected adult and sub-adult white rhinoceros distribution data over a 15 month period, calculating individual range size using kernel density estimation analysis within a GIS. From this, terrain selectivity was calculated using 50% and 95% kernels to extract terrain composition values. Jacob's correction of the Ivlev's selectivity index was subsequently applied to the terrain composition of each individual to identify trends in selectivity. Results reveal that adult males hold exclusive territories considerably smaller than those found in previous work conducted in "open" or large reserves. Similarly, results for the size of male versus female territories were also not in keeping with those from previous field studies, with males, rather than females, having the larger territory requirement. Terrain selection for both genders and age classes (adult and sub-adult showed a strong preference for open grassland and avoidance of hill slope and riparian terrains. This research reveals white rhinoceros terrain selection preferences and how they influence range requirements in small, closed reserves. We conclude that this knowledge will be valuable in future white rhinoceros conservation management in small private game reserves, particularly in decisions surrounding removal of surplus individuals or augmentation of existing populations, calculation of reserve carrying capacity and future private reserve acquisition.

  20. Ecological niche modeling of the invasive potential of Nile tilapia Oreochromis niloticus in African river systems: concerns and implications for the conservation of indigenous congenerics

    CSIR Research Space (South Africa)

    Zengeya, TA

    2013-07-01

    Full Text Available tilapia in its native and introduced ranges are not congruent. Nile tilapia exhibited broad invasive potential over most of southern Africa that overlaps the natural range of endemic congenerics. Of particular concern are areas which are free of exotic...

  1. On the ecology of the fauna of stones in the current in a South African river supporting a very large simulium (Diptera) population

    CSIR Research Space (South Africa)

    Chutter, FM

    1968-12-01

    Full Text Available the studies described here were made. The first aim of this work was to record the density of the Simulium larvae and also of the other invertebrate animals in the river at different times of the year from Warrenton down to Barkly West....

  2. Microhabitat use by fishes in the middle course of the River Gambia in the Niokolo Koba National Park, Senegal: a unique example of an undisturbed West African assemblage

    Czech Academy of Sciences Publication Activity Database

    Reichard, Martin

    2008-01-01

    Roč. 72, č. 7 (2008), s. 1815-1824 ISSN 0022-1112 R&D Projects: GA AV ČR IAA6093404 Institutional research plan: CEZ:AV0Z60930519 Keywords : fish-habitat association * resource partitioning * Soudanian River Subject RIV: EH - Ecology, Behaviour Impact factor: 1.246, year: 2008

  3. Preliminary assessment of risk of ozone impacts to maize (Zea mays) in Southern Africa

    CSIR Research Space (South Africa)

    Van Tienhoven, AM

    2006-03-01

    Full Text Available Surface ozone concentrations in southern Africa exceed air quality guidelines set to protect agricultural crops. This paper addresses a knowledge gap by performing a preliminary assessment of potential ozone impacts on vegetation in southern African...

  4. THE AFRICAN ASSOCIATION FOR LEXICOGRAPHY

    African Journals Online (AJOL)

    Riette Ruthven

    1.4 Target group. All known individuals, institutions and bodies involved in lexicography and ... It was felt that a professional association for Southern African lexicography .... for Lexicography, Lexikos also became the official mouthpiece of AFRILEX. .... language teachers and journalists — those who cannot do their specific.

  5. The influence of feeding on the evolution of sensory signals: a comparative test of an evolutionary trade-off between masticatory and sensory functions of skulls in southern African horseshoe bats (Rhinolophidae).

    Science.gov (United States)

    Jacobs, D S; Bastian, A; Bam, L

    2014-12-01

    The skulls of animals have to perform many functions. Optimization for one function may mean another function is less optimized, resulting in evolutionary trade-offs. Here, we investigate whether a trade-off exists between the masticatory and sensory functions of animal skulls using echolocating bats as model species. Several species of rhinolophid bats deviate from the allometric relationship between body size and echolocation frequency. Such deviation may be the result of selection for increased bite force, resulting in a decrease in snout length which could in turn lead to higher echolocation frequencies. If so, there should be a positive relationship between bite force and echolocation frequency. We investigated this relationship in several species of southern African rhinolophids using phylogenetically informed analyses of the allometry of their bite force and echolocation frequency and of the three-dimensional shape of their skulls. As predicted, echolocation frequency was positively correlated with bite force, suggesting that its evolution is influenced by a trade-off between the masticatory and sensory functions of the skull. In support of this, variation in skull shape was explained by both echolocation frequency (80%) and bite force (20%). Furthermore, it appears that selection has acted on the nasal capsules, which have a frequency-specific impedance matching function during vocalization. There was a negative correlation between echolocation frequency and capsule volume across species. Optimization of the masticatory function of the skull may have been achieved through changes in the shape of the mandible and associated musculature, elements not considered in this study. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  6. Phylogenetic status of brown trout Salmo trutta populations in five rivers from the southern Caspian Sea and two inland lake basins, Iran: a morphogenetic approach.

    Science.gov (United States)

    Hashemzadeh Segherloo, I; Farahmand, H; Abdoli, A; Bernatchez, L; Primmer, C R; Swatdipong, A; Karami, M; Khalili, B

    2012-10-01

    Interrelationships, origin and phylogenetic affinities of brown trout Salmo trutta populations from the southern Caspian Sea basin, Orumieh and Namak Lake basins in Iran were analysed from complete mtDNA control region sequences, 12 microsatellite loci and morphological characters. Among 129 specimens from six populations, seven haplotypes were observed. Based on mtDNA haplotype data, the Orumieh and southern Caspian populations did not differ significantly, but the Namak basin-Karaj population presented a unique haplotype closely related to the haplotypes of the other populations (0·1% Kimura two-parameter, K2P divergence). All Iranian haplotypes clustered as a distinct group within the Danube phylogenetic grouping, with an average K2P distance of 0·41% relative to other Danubian haplotypes. The Karaj haplotype in the Namak basin was related to a haplotype (Da26) formerly identified in the Tigris basin in Turkey, to a Salmo trutta oxianus haplotype from the Aral Sea basin, and to haplotype Da1a with two mutational steps, as well as to other Iranian haplotypes with one to two mutational steps, which may indicate a centre of origin in the Caspian basin. In contrast to results of the mtDNA analysis, more pronounced differentiation was observed among the populations studied in the morphological and microsatellite DNA data, except for the two populations from the Orumieh basin, which were similar, possibly due to anthropogenic causes. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  7. Defining and modeling the soil geochemical background of heavy metals from the Hengshi River watershed (southern China): Integrating EDA, stochastic simulation and magnetic parameters

    International Nuclear Information System (INIS)

    Zhou Xu; Xia Beicheng

    2010-01-01

    It is crucial to separate the soil geochemical background concentrations from anthropogenic anomalies and to provide a realistic environmental geochemical map honoring the fluctuations in original data. This study was carried out in the Hengshi River watershed, north of Guangdong, China and the method proposed combined exploratory data analysis (EDA), sequential indicator co-simulation (SIcS) and the ratio of isothermal remnant magnetization (S 100 = -IRM -100mT /SIRM). The results showed that this is robust procedure for defining and mapping soil geochemical background concentrations in mineralized regions. The rock magnetic parameter helps to improve the mapping process by distinguishing anthropogenic influences. In this study, the geochemical backgrounds for four potentially toxic heavy metals (copper 200 mg/kg; zinc 230 mg/kg; lead 190 mg/kg and cadmium 1.85 mg/kg) Cu, Zn and Cd exceeded the soil Grade II limits (for pH < 6.5) from the Chinese Environmental Quality Standard for Soils (GB 15618-1995) (EQSS) which are 100, 200, 250 and 0.3 mg/kg for Cu, Zn, Pb and Cd, respectively. In particular, the geochemical background level for Cd exceeds standard six times. Results suggest that local public health is at high-risk along the riparian region of the Hengshi River, although the watershed ecosystem has not been severely disturbed.

  8. Use of food resources and resource partitioning among five syntopic species of Hypostomus (Teleostei: Loricariidae in an Atlantic Forest river in southern Brazil

    Directory of Open Access Journals (Sweden)

    Vinicius Abilhoa

    Full Text Available ABSTRACT We analyzed the diet and resource partitioning among five syntopic species of Hypostomus Lacépède, 1803 in the Corumbataí River in southeastern Brazil. The gut contents of 352 individuals were assessed and 21 food items were identified and quantified under an optical microscope. The food items found in the gut contents indicate that these suckermouth loricariids are bottom-dwelling detritivorous/periphytivorous catfishes. PERMANOVA and SIMPER analyses indicated variation in the consumption of some resources, and the contribution of periphytic algae was primarily responsible for such dissimilarity. ECOSIM analyses of dietary overlap showed evidence of resource sharing among all species in the dry and rainy periods. This is most likely the result of the predominance of detritus and autochthonous items such as algae and aquatic immature insects in all gut contents. Our data suggest that trophic resources available in the Corumbataí River are explored and partitioned among Hypostomus species, all specialized in surface-grazing foraging behaviour.

  9. Temporal variability and annual budget of inorganic dissolved matter in Andean Pacific Rivers located along a climate gradient from northern Ecuador to southern Peru

    Science.gov (United States)

    Moquet, Jean-Sébastien; Guyot, Jean-Loup; Morera, Sergio; Crave, Alain; Rau, Pedro; Vauchel, Philippe; Lagane, Christelle; Sondag, Francis; Lavado, Casimiro Waldo; Pombosa, Rodrigo; Martinez, Jean-Michel

    2018-01-01

    In Ecuador and Peru, geochemical information from Pacific coastal rivers is limited and scarce. Here, we present an unedited database of major element concentrations from five HYBAM observatory stations monitored monthly between 4 and 10 years, and the discrete sampling of 23 Andean rivers distributed along the climate gradient of the Ecuadorian and Peruvian Pacific coasts. Concentration (C) vs. discharge (Q) relationships of the five monitored basins exhibit a clear dilution behavior for evaporites and/or pyrite solutes, while the solute concentrations delivered by other endmembers are less variable. Spatially, the annual specific fluxes for total dissolved solids (TDS), Ca2+, HCO3-, K+, Mg2+, and SiO2 are controlled on the first order by runoff variability, while Cl-, Na+ and SO42- are controlled by the occurrence of evaporites and/or pyrite. The entire Pacific basin in Ecuador and Peru exported 30 Mt TDS·yr-1, according to a specific flux of ∼70 t·km-2·yr-1. This show that, even under low rainfall conditions, this orogenic context is more active, in terms of solute production, than the global average.

  10. African Anthropologist

    African Journals Online (AJOL)

    PROMOTING ACCESS TO AFRICAN RESEARCH ... It provides a forum for African and Africanist anthropologists to publish research reports, articles, book ... A Qualitative Exploration · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  11. Groundwater discharge in high-mountain watersheds: A valuable resource for downstream semi-arid zones. The case of the Bérchules River in Sierra Nevada (Southern Spain).

    Science.gov (United States)

    Jódar, Jorge; Cabrera, José Antonio; Martos-Rosillo, Sergio; Ruiz-Constán, Ana; González-Ramón, Antonio; Lambán, Luis Javier; Herrera, Christian; Custodio, Emilio

    2017-09-01

    Aquifers in permeable formations developed in high-mountain watersheds slow down the transfer of snowmelt to rivers, modifying rivers' flow pattern. To gain insight into the processes that control the hydrologic response of such systems the role played by groundwater in an alpine basin located at the southeastern part of the Iberian Peninsula is investigated. As data in these environments is generally scarce and its variability is high, simple lumped parameter hydrological models that consider the groundwater component and snow accumulation and melting are needed. Instead of using existing models that use many parameters, the Témez lumped hydrological model of common use in Spain and Ibero-American countries is selected and modified to consider snow to get a simplified tool to separate hydrograph components. The result is the TDD model (Témez-Degree Day) which is applied in a high mountain watershed with seasonal snow cover in Southern Spain to help in quantifying groundwater recharge and determining the groundwater contribution to the outflow. Average groundwater recharge is about 23% of the precipitation, and groundwater contribution to total outflow ranges between 70 and 97%. Direct surface runoff is 1% of precipitation. These values depend on the existence of snow. Results are consistent with those obtained with chloride atmospheric deposition mass balances by other authors. They highlight the important role of groundwater in high mountain areas, which is enhanced by seasonal snow cover. Results compare well with other areas. This effect is often neglected in water planning, but can be easily taken into account just by extending the water balance tool in use, or any other, following the procedure that has being developed. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. The distribution and speciation of trace metals in surface sediments from the Pearl River Estuary and the Daya Bay, Southern China

    International Nuclear Information System (INIS)

    Yu Xiujuan; Yan Yan; Wang Wenxiong

    2010-01-01

    Surface sediments collected from the Pearl River Estuary (PRE) and the Daya Bay (DYB) were analyzed for total metal concentrations and chemical phase partitioning. The total concentrations of Cr, Cu, Ni, Pb, and Zn in the PRE were obviously higher than those in DYB. The maximum concentrations of trace metals in DYB occurred in the four sub-basins, especially in Dapeng Cove, while the concentrations of these metals in the western side of the PRE were higher than those in the east side. Such distribution pattern was primarily due to the different hydraulic conditions and inputs of anthropogenic trace metals. The chemical partitioning of metals analyzed by the BCR sequential extraction method showed that Cr, Ni, and Zn of both areas were present dominantly in the residual fraction, while Pb was found mostly in the non-residual fractions. The partitioning of Cu showed a significant difference between the two areas.

  13. Microplastics in Inland African Waters

    DEFF Research Database (Denmark)

    Khan, Farhan; Mayoma, Bahati Sosthenes; Biginagwa, Fares John

    2017-01-01

    As the birthplace of our species, the African continent holds a unique place in human history. Upon entering a new epoch, the Anthropocene defined by human-driven influences on earth systems, and with the recognition that plastic pollution is one of the hallmarks of this new age, remarkably little...... is known about the presence, sources, and fate of plastics (and microplastics (MPs)) within African waters. Research in marine regions, most notably around the coast of South Africa, describes the occurrence of MPs in seabirds and fish species. More recently environmental sampling studies in the same area...... have quantified plastics in both the water column and sediments. However, despite Africa containing some of the largest and deepest of the world’s freshwater lakes, including Lakes Victoria and Tanganyika as part of the African Great Lakes system, and notable freshwater rivers, such as the River Congo...

  14. A Europe-wide system for assessing the quality of rivers using macroinvertebrates: the AQEM Project* and its importance for southern Europe (with special emphasis on Italy

    Directory of Open Access Journals (Sweden)

    Joanna L. KEMP

    2001-09-01

    Full Text Available The AQEM Project aims to develop a Europe-wide system for monitoring the ecological quality of rivers using macroinvertebrates, to satisfy the requirements of the EU Water Framework Directive. Three main types of anthropogenic perturbation are being investigated: morphological degradation, water (organic pollution and acidification (the last is not under investigation in Italy. The selection of reference and impaired study sites is discussed. Particular attention is paid to the problems encountered when defining reference conditions. The initial stages of the project highlighted the lack of a Europe-wide definition of river types. The future development of such a typology from the AQEM database is discussed. The standard AQEM data gathering methods are presented, from background information about sites to the microhabitat-based macroinvertebrate sampling method. The extended fieldwork methods used in Italy are described. These included the separate analysis of the invertebrate assemblages from each replicate, the recording of additional microhabitat variables for each replicate and the completion of large-scale survey techniques for each site (including RHS. The extended method was designed to enhance the important ecological information available from the dataset, particularly relevant in Italy where significant gaps exist in the taxonomic and ecological knowledge of many macroinvertebrate taxa. Preliminary and expected findings are presented, including examples of the range and habitat selection of two species of Ephemeroptera endemic to Italy, as well as data relating to the number of taxa found at a site with increasing numbers of microhabitat replicates taken. The importance of the AQEM Project not only for biomonitoring, but also for ecology, taxonomy and conservation, in Italy and for the south of Europe in general, is emphasised.

  15. New Zircon U-Pb Age Constrain of the Origin of Devil's River Uplift (SW Texas) and Insights into the Late Proterozoic and Paleozoic Evolution of the Southern Margin of Laurentia

    Science.gov (United States)

    Rodriguez, E.; Dickerson, P. W.; Stockli, D. F.

    2017-12-01

    The Devils River Uplift (DRU) in SW Texas records the evolution of the southern Laurentian margin from Grenvillian orogenesis and assembly of Rodinia, to its fragmentation by rifting, and to the amalgamation of Pangaea. It was cored by a well (Shell No. 1 Stewart), penetrating Precambrian gneisses and Cambrian metasediments and sandstones. New zircon LA-ICP-MS data from a total of 10 samples elucidate the crystallization and depositional ages, as well as the detrital provenance, of Precambrian and Cambrian rocks from the DRU. Zircons from five Precambrian crystalline basement samples (6000-9693') yield uniform U-Pb crystallization ages of 1230 Ma that are similar to ages for young gneisses of the Valley Spring Domain (Llano uplift) in central Texas, where they mark the cessation of arc magmatism within the Grenville orogenic belt. The 1230 Ma igneous basement is overlain by L.-M. Cambrian metasedimentary rocks ( 4000-6000') with maximum depositional ages of 533-545 Ma. Detrital zircons from Cambrian strata are dominated by a 1070-1080 Ma population, likely derived from basement units exposed in Texas (Llano uplift, Franklin Mts.), with minor contributions from local 1230 Ma Precambrian basement and the 1380-1500 Ma Granite Rhyolite Province. The L.-M. Cambrian interval is dominated (>80%) by Neoproterozoic detrital magmatic zircons with two major distinct age clusters at 570-700 Ma and 780-820 Ma, supporting a two-stage Rodinia rift model and providing strong evidence for major Cryogenian-Eocambrian intraplate magmatism along the southern margin of Rodinia. Moreover, detrital zircon signatures for L.-M. and U. Cambrian strata strongly correlate with those from the Cuyania terrane of W. Argentina - notably the W. Sierras Pampeanas (Sa. Pie de Palo, Sa. de Maz): 1230 Ma from metasandstones (PdP); 1081-1038 Ma from metasiliciclastics (PdP, SdM); Cryogenian-Eocambrian [774 & 570 Ma] plutons (SdM, PdP). In summary, these new zircon U-Pb data from DRU in SW Texas show

  16. Africanization in the United States: replacement of feral European honeybees (Apis mellifera L.) by an African hybrid swarm.

    Science.gov (United States)

    Pinto, M Alice; Rubink, William L; Patton, John C; Coulson, Robert N; Johnston, J Spencer

    2005-08-01

    The expansion of Africanized honeybees from South America to the southwestern United States in feral population from the southern United States undergoing Africanization. Our microsatellite data showed that (1) the process of Africanization involved both maternal and paternal bidirectional gene flow between European and Africanized honeybees and (2) the panmitic European population was replaced by panmitic mixtures of A. m. scutellata and European genes within 5 years after Africanization. The post-Africanization gene pool (1998-2001) was composed of a diverse array of recombinant classes with a substantial European genetic contribution (mean 25-37%). Therefore, the resulting feral honeybee population of south Texas was best viewed as a hybrid swarm.

  17. African Journals Online: African Studies

    African Journals Online (AJOL)

    Items 51 - 56 of 56 ... Research Review of the Institute of African Studies. Please note: As of 2013 the Research Review of the Institute of African Studies is now publishing under the title Contemporary Journal of African Studies. You can view the CJAS pages on AJOL here: http://www.ajol.info/index.php/contjas/index.

  18. The genetic prehistory of southern Africa.

    Science.gov (United States)

    Pickrell, Joseph K; Patterson, Nick; Barbieri, Chiara; Berthold, Falko; Gerlach, Linda; Güldemann, Tom; Kure, Blesswell; Mpoloka, Sununguko Wata; Nakagawa, Hirosi; Naumann, Christfried; Lipson, Mark; Loh, Po-Ru; Lachance, Joseph; Mountain, Joanna; Bustamante, Carlos D; Berger, Bonnie; Tishkoff, Sarah A; Henn, Brenna M; Stoneking, Mark; Reich, David; Pakendorf, Brigitte

    2012-01-01

    Southern and eastern African populations that speak non-Bantu languages with click consonants are known to harbour some of the most ancient genetic lineages in humans, but their relationships are poorly understood. Here, we report data from 23 populations analysed at over half a million single-nucleotide polymorphisms, using a genome-wide array designed for studying human history. The southern African Khoisan fall into two genetic groups, loosely corresponding to the northwestern and southeastern Kalahari, which we show separated within the last 30,000 years. We find that all individuals derive at least a few percent of their genomes from admixture with non-Khoisan populations that began ∼1,200 years ago. In addition, the East African Hadza and Sandawe derive a fraction of their ancestry from admixture with a population related to the Khoisan, supporting the hypothesis of an ancient link between southern and eastern Africa.

  19. Assessment of hydrochemical trends in the highly anthropised Guadalhorce River basin (southern Spain) in terms of compliance with the European groundwater directive for 2015.

    Science.gov (United States)

    Urresti-Estala, Begoña; Gavilán, Pablo Jiménez; Pérez, Iñaki Vadillo; Cantos, Francisco Carrasco

    2016-08-01

    One of the key aspects introduced by the European Water Framework Directive 2000/60/EC (WFD) and developed by Groundwater Directive 2006/118/EC was the need to analyse pollution trends in groundwater bodies in order to meet the environmental objectives set in Article 4 WFD. According to this Directive, the main goal of "good status" should be achieved by the year 2015, and having reached this horizon, now is a suitable time to assess the changes that have taken place with the progressive implementation of the WFD. An extensive database is available for the Guadalhorce River basin, and this was used not only to identify in groundwater but also to draw real conclusions with respect to the degree of success in meeting the targets established for this main deadline (2015) The geographic and climate context of the Guadalhorce basin has facilitated the development of a variety of economic activities, but the one affecting the largest surface area is agriculture (which is practised on over 50 % of the river basin). The main environmental impacts identified in the basin aquifers arise from the widespread use of fertilisers and manures, together with the input of sewage from population centres. In consequence, some of the groundwater bodies located in the basin have historically had very high nitrate concentrations, often exceeding 200 mg/L. In addition, return flows, the use of fertilisers and other pressures promote the entry of other pollutants into the groundwater, as well as the salinisation of the main aquifers in the basin. In order to assess the hydrochemical changes that have taken place since the entry into force of the WFD, we performed a detailed trends analysis, based on data from the official sampling networks. In some cases, over 35 years of water quality data are available, but these statistics also present significant limitations, due to some deficiencies in the design or management; thus, data are missing for many years, the results are subject to

  20. Site response variation due to the existence of near-field cracks based on strong motion records in the Shi-Wen river valley, southern Taiwan

    Science.gov (United States)

    Wu, Chi-Shin; Yu, Teng-To; Peng, Wen-Fei; Yeh, Yeoin-Tein; Lin, Sih-Siao

    2014-10-01

    Site effect analysis has been applied to investigate soil classification, alluvium depth, and fracture detection, although the majority of previous studies have typically focused only on the response of large-scale single structures. In contrast, we investigated the site effect for small-scale cracks using a case study in southern Taiwan to provide a means of monitoring slope stability or foundation integrity in situ using only an accelerometer. We adopted both the reference site and horizontal-to-vertical spectral ratio methods. We obtained seismographs associated with the typhoon-related development of a crack set (52 m long, 5 m deep) in a steep slope and compared the resonance frequency between two conditions (with and without cracks). Moreover, we divided the seismic waves into P, S, and coda waves and examined the seismic source effect. Our results demonstrate that frequencies of 14.5-17.5 Hz are most sensitive to these cracks, particularly for the E-W component of the P-waves, which coincides with the crack’s strike. Peak ground acceleration, which is controlled by seismic moment and attenuated distance, is another important factor determining the resonance results. Our results demonstrate that the ratio of temporal seismic waves can be used to detect the existence of nearby subsurface cracks.