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PT J
AU Robertson, MP
Villet, MH
Fairbanks, DHK
Henderson, L
Higgins, SI
Hoffmann, JH
Le Maitre, DC
Palmer, AR
Riggs, I
Shackleton, CM
Zimmermann, HG
AF Robertson, MP
Villet, MH
Fairbanks, DHK
Henderson, L
Higgins, SI
Hoffmann, JH
Le Maitre, DC
Palmer, AR
Riggs, I
Shackleton, CM
Zimmermann, HG
TI A proposed prioritization system for the management of invasive alien
plants in South Africa
SO SOUTH AFRICAN JOURNAL OF SCIENCE
LA English
DT Article
AB EVERY COUNTRY HAS WEED SPECIES WHOSE presence conflicts in some way with human management objectives and needs. Resources for research and control are limited, so priority should be given to species that are the biggest problem. The prioritization system described in this article was designed to assess objectively research and control priorities of invasive alien plants at a national scale in South Africa. The evaluation consists of seventeen criteria, grouped into five modules, that assess invasiveness, spatial characteristics, potential impact, potential for control, and conflicts of interest for each plant species under consideration. Total prioritization scores, calculated from criterion and module scores, were used to assess a species' priority. Prioritization scores were calculated by combining independent assessments provided by several experts, thus increasing the reliability of the rankings. The total confidence score, a separate index, indicates the reliability and availability of data used to make an assessment. Candidate species for evaluation were identified and assessed by several experts using the prioritization system. The final ranking was made by combining two separate indices, the total prioritization score and the total confidence score. This approach integrates the plant's perceived priority with an index of data reliability. Of the 61 species assessed, those with the highest ranks (Lantana camara, Chromolaena odorata and Opuntia ficus-indica) had high prioritization and high confidence scores, and are thus of most concern. Those species with the lowest ranks, for example, Harrisia martinii, Opuntia spinulifera and Opuntia exaltata, had low prioritization scores and high confidence scores, and thus are of least concern. Our approach to ranking weeds offers several advantages over existing systems because it is designed for multiple assessors based on the Delphi decision-making technique, the criteria contribute equally to the total score, and the system can accommodate incomplete data on a species. Although the choice of criteria may be criticized and the system has certain limitations, it appears to have delivered credible results.
C1 Univ Pretoria, Dept Zool & Entomol, ZA-0002 Pretoria, South Africa.
Agr Res Council, Range & Forage Inst, ZA-6140 Grahamstown, South Africa.
Rhodes Univ, Dept Zool & Entomol, ZA-6140 Grahamstown, South Africa.
Univ Pretoria, Ctr Environm Studies, ZA-0002 Pretoria, South Africa.
UFZ Helmholtz Ctr Environm Res, D-04318 Leipzig, Germany.
Univ Cape Town, Dept Zool, ZA-7701 Rondebosch, South Africa.
CSIR, Div Water Environm & Forestry Technol, ZA-7600 Stellenbosch, South Africa.
Natl Dept Agr, Directorate Land Use & Soil Management, ZA-0001 Pretoria, South Africa.
Rhodes Univ, Dept Environm Sci, ZA-6140 Grahamstown, South Africa.
Weeds Res, Natl Bot Inst, Plant Protect Res Inst, Agr Res Council, ZA-0001 Pretoria, South Africa.
RP Robertson, MP (reprint author), Univ Pretoria, Dept Zool & Entomol, ZA-0002 Pretoria, South Africa.
EM mrobertson@zoology.up.ac.za
RI Villet, Martin/B-5811-2011; Robertson, Mark/A-5640-2011; Higgins,
Steven/A-5138-2012; Shackleton, Charlie/F-4177-2014;
OI Higgins, Steven/0000-0001-5695-9665; Villet, Martin/0000-0002-4335-5667;
Shackleton, Charlie/0000-0002-8489-6136
NR 24
TC 21
Z9 27
U1 2
U2 10
PU ACAD SCIENCE SOUTH AFRICA A S S AF
PI LYNWOOD RIDGE
PA PO BOX 72135, LYNWOOD RIDGE 0040, SOUTH AFRICA
SN 0038-2353
J9 S AFR J SCI
JI S. Afr. J. Sci.
PD JAN-FEB
PY 2003
VL 99
IS 1-2
BP 37
EP 43
PG 7
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 678HR
UT WOS:000182861800014
ER
PT J
AU Berman, PAM
Baumgarten, I
Viljoen, DL
AF Berman, PAM
Baumgarten, I
Viljoen, DL
TI Effect of oral fructose on ethanol elimination from the bloodstream
SO SOUTH AFRICAN JOURNAL OF SCIENCE
LA English
DT Article
ID ALCOHOL METABOLISM; GLUCOSE
AB ALCOHOL HAS BEEN IDENTIFIED AS A MAJOR factor contributing to traffic accidents in South Africa, affecting both drivers and pedestrians alike. An agent capable of facilitating ethanol metabolism safely and effectively is of potential value in reducing the frequency of such incidents, and for individuals wishing to reduce their blood alcohol to levels below the legal limit before taking control of a vehicle. Here we show that fructose, at a dose of 1 g/kg, fulfils the criteria for such an agent. When ingested by healthy volunteers who had imbibed ethanol equivalent to 8 standard tots, it reduced the time required to attain a legal blood alcohol level (50 mg%) by approximately 70 min (n = 9). When ingested before a dose of alcohol equivalent to a double tot, fructose reduced both the magnitude and duration of the subsequent increase in blood alcohol; mean peak height, area under the curve, and time taken to reach zero were 39%, 32% and 51%, respectively, of that observed in the absence of fructose (n = 12). We conclude that, whether taken after imbibing alcoholic beverages or prophylactically before commencing drinking, oral fructose significantly lowers blood alcohol levels and reduces the time required for alcohol to disappear from the bloodstream.
C1 Univ Cape Town, Dept Chem Pathol, Sch Med, ZA-7925 Observatory, South Africa.
Univ Cape Town, Fdn Alcohol Related Res, Sch Med, ZA-7925 Observatory, South Africa.
RP Berman, PAM (reprint author), Univ Cape Town, Dept Chem Pathol, Sch Med, ZA-7925 Observatory, South Africa.
EM pete@chempath.uct.ac.za
NR 18
TC 7
Z9 7
U1 1
U2 2
PU ACAD SCIENCE SOUTH AFRICA A S S AF
PI LYNWOOD RIDGE
PA PO BOX 72135, LYNWOOD RIDGE 0040, SOUTH AFRICA
SN 0038-2353
J9 S AFR J SCI
JI S. Afr. J. Sci.
PD JAN-FEB
PY 2003
VL 99
IS 1-2
BP 47
EP 50
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 678HR
UT WOS:000182861800016
ER
PT J
AU van Beers, D
Graedel, TE
AF van Beers, D
Graedel, TE
TI The magnitude and spatial distribution of in-use copper stocks in Cape
Town, South Africa
SO SOUTH AFRICAN JOURNAL OF SCIENCE
LA English
DT Article
AB As a major urban centre, the city of Cape Town possesses a large reservoir of In-use copper. As the metal's uses become obsolete, the copper will gradually become available for re-use, should that prove technically feasible and economically desirable. To evaluate this resource, we identified the principal uses of the metal in the city and its surroundings, quantified them, and estimated their in-use lifetime. We used this information to estimate in-use stock at about 110 Gg (110 million kg) copper and to predict end-of-life flows for several decades into the future. A model, using geographic information system (GIS) software, was developed to assess contemporary stocks spatially and to predict future stocks according to selected uses. The largest stocks are in the area formerly administered by the Central Cape Town municipal council, that is expected also to be the principal copper reservoir in the future. Impoverished areas turned out to have higher spatial densities of copper than wealthy suburbs, because of their high-density housing. The total stock of in-use copper in Cape Town today appears to be less than 1% of South Africa's mineral reserves of the metal, but Its recovery and re-use appears to be justified because of its relatively low associated environmental cost. We conclude that if all end-of-life copper is reprocessed, rather than discarded or transferred outside the region, it could supply up to 60% of Cape Town's copper demand over the next three decades.
C1 Yale Univ, Ctr Ind Ecol, New Haven, CT 06511 USA.
RP van Beers, D (reprint author), Yale Univ, Ctr Ind Ecol, 285 Prospect St, New Haven, CT 06511 USA.
NR 14
TC 17
Z9 17
U1 2
U2 8
PU ACAD SCIENCE SOUTH AFRICA A S S AF
PI LYNWOOD RIDGE
PA PO BOX 72135, LYNWOOD RIDGE 0040, SOUTH AFRICA
SN 0038-2353
J9 S AFR J SCI
JI S. Afr. J. Sci.
PD JAN-FEB
PY 2003
VL 99
IS 1-2
BP 61
EP 69
PG 9
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 678HR
UT WOS:000182861800020
ER
PT J
AU Reason, CJC
Jagadheesha, D
Tadross, M
AF Reason, CJC
Jagadheesha, D
Tadross, M
TI A model investigation of inter-annual winter rainfall variability over
southwestern South Africa and associated ocean-atmosphere interaction
SO SOUTH AFRICAN JOURNAL OF SCIENCE
LA English
DT Article
ID CIRCULATION; TEMPERATURE; HEMISPHERE
AB We have investigated the variability of inter-annual winter rainfall over the southwestern Cape region of South Africa and associated large-scale atmosphere-ocean interaction upstream over the South Atlantic using the HadAM3 atmospheric general circulation model. This model was run for the period from 1990 to 1999 using mean monthly global sea-surface temperature (SST) as surface boundary condition over the global ocean. Diagnostics of winter (May to September) model output averaged over 1990-99 suggest that the HadAM3 model represents the general circulation in the South Atlantic/African sector reasonably well for this season at least. In addition, model years with wet and dry winters over the study area tended also to be those that were observed to be anomalously wet or dry. Wet minus dry season composite fields were used to investigate the model's inter-annual variability. The composite difference fields for low- and mid-level winds, sea-level pressure, and moisture flux all Indicated wet winters being associated with increased inflow from tropical South America (originating in the equatorial western Atlantic at low levels) contributing relatively moist air to the westerly flow heading towards the southwestern Cape. A stronger jet over the South Atlantic promoted the passage of storms towards the Cape. Large areas of cyclonic vorticity anomalies, enhanced eddy activity, increased thickness in the lower atmosphere and low-level convergence near and upstream of the southwestern Cape in the model composite differences all favoured Increased storm systems as well as their local intensification, implying enhanced rainfall. The results presented here suggest that the model can represent the inter-annual variability of winter rainfall over the study region and shed light on the mechanisms potentially associated with anomalously wet winters there.
C1 Univ Cape Town, Dept Geog & Environm Sci, ZA-7701 Rondebosch, South Africa.
Univ Cape Town, Dept Oceanog, ZA-7701 Rondebosch, South Africa.
RP Reason, CJC (reprint author), Univ Cape Town, Dept Geog & Environm Sci, Private Bag, ZA-7701 Rondebosch, South Africa.
EM cjr@egs.uct.ac.za
NR 13
TC 4
Z9 4
U1 1
U2 3
PU ACAD SCIENCE SOUTH AFRICA A S S AF
PI LYNWOOD RIDGE
PA PO BOX 72135, LYNWOOD RIDGE 0040, SOUTH AFRICA
SN 0038-2353
J9 S AFR J SCI
JI S. Afr. J. Sci.
PD JAN-FEB
PY 2003
VL 99
IS 1-2
BP 75
EP 80
PG 6
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 678HR
UT WOS:000182861800022
ER
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