scholarly journals Salicornia L. (Amaranthaceae) in South Africa and Namibia: rapid spread and ecological diversification of cryptic species

2013 ◽  
Vol 172 (2) ◽  
pp. 175-186 ◽  
Author(s):  
Anita Slenzka ◽  
Ladislav Mucina ◽  
Gudrun Kadereit
Keyword(s):  
South Africa ◽  
Cryptic Species ◽  
Ecological Diversification ◽  
Rapid Spread

Two new species of Acontias (Acontinae, Scincidae) from the Mpumalanga Highveld escarpment of South Africa

Zootaxa ◽  
2018 ◽  
Vol 4429 (1) ◽  
pp. 89 ◽  
Author(s):  
WERNER CONRADIE ◽  
THEO BUSSCHAU ◽  
SHELLEY EDWARDS
Keyword(s):  
South Africa ◽  
New Species ◽  
Cryptic Species ◽  
Biodiversity Hotspot ◽  
Two New Species ◽  
Disjunct Populations ◽  
African Genus ◽  
Distinguishing Character

The African genus of fossorial legless lizards (Acontias Cuvier) currently comprises 26 species and subspecies. In a recent study on the two disjunct populations of Acontias breviceps Essex, the presence of cryptic species was discovered. Here, we increase the sampling size and describe these disjunct populations from the Mpumalanga Escarpment of South Africa as new species. The new species differ from congeners based on a combination of factors, including the number of midbody, ventral, and subcaudal scale counts, ventral pigmentation, allopatric distributions, and genetic divergences. The new species are genetically distant from nominal A. breviceps, with which it shares overall pigmentation and scalation. The new description adds to the growing number of Mpumalanga escarpment endemic reptiles, and highlights the area as a biodiversity hotspot. The use of vertebral counts as a distinguishing character between species is briefly discussed. 

scholarly journals The Establishment and Rapid Spread of Sagittaria Platyphylla in South Africa

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1472
Author(s):  
Mpilonhle S. Ndlovu ◽  
Julie A. Coetzee ◽  
Menzi M. Nxumalo ◽  
Reshnee Lalla ◽  
Ntombifuthi Shabalala ◽  
...  
Keyword(s):  
South Africa ◽  
Aquatic Macrophyte ◽  
Management Strategies ◽  
Control Measures ◽  
Invasive Weed ◽  
Mechanical Control ◽  
Potential Control ◽  
Control Option ◽  
Rapid Spread ◽  
Lotic System

Sagittaria platyphylla Engelm. (Alismataceae) is a freshwater aquatic macrophyte that has become an important invasive weed in freshwater systems in South Africa, New Zealand, Australia, and recently China. In South Africa, due to its rapid increase in distribution and ineffective control options, it is recognised as one of the country’s worst invasive aquatic alien plants. In this paper, we investigate the spread of the plant since its first detection in 2008, and the management strategies currently carried out against it. Despite early detection and rapid response programmes, which included chemical and mechanical control measures, the plant was able to spread both within and between sites, increasing from just one site in 2008 to 72 by 2019. Once introduced into a lotic system, the plant was able to spread rapidly, in some cases up to 120 km within 6 years, with an average of 10 km per year. The plant was successfully extirpated at some sites, however, due to the failure of chemical and mechanical control, biological control is currently being considered as a potential control option.

An Arsenic-resistant Tick and its Control with “Gammexane” Dips.—Part II

1949 ◽  
Vol 40 (2) ◽  
pp. 207-226 ◽  
Author(s):  
A. B. M. Whitnall ◽  
B. Bradford
Keyword(s):  
South Africa ◽  
Laboratory Tests ◽  
Chemical Analyses ◽  
Rapid Spread ◽  
Single Host ◽  
Biological Tests ◽  
Excellent Control ◽  
Oil Emulsions ◽  
Paralysis Tick

The rapid spread of the single host arsenic-resistant blue tick, B. decoloratus, a transmitter of piroplasmosis and anaplasmosis, seriously affected a large and important cattle ranching area in South Africa.Biological tests, using the laboratory technique described in an earlier paper, enabled the most effective “Gammexane” preparations to be rapidly selected from numbers of experimental dips. The technique was also employed as a supplement to chemical analyses of dip wash samples where only the total hexachlorocyclohexane and not gamma isomer was estimated. Twenty-thousand adult female ticks were used in these in vitro tests. Oil emulsions seemed more active than dispersible powders or pastes, but all tests indicated that 50 parts per million “Gammexane” should satisfactorily control the tick in the field.Laboratory tests with larvae of the blue tick showed that “Gammexane” had a persistent action and was very toxic to this stage of the tick. Excellent control of larval ticks could be anticipated in the field.In vitro tests indicated that “Gammexane” was effective against the two- and three-host ticks, R. evertsi, R. appendiculatus, A. hebraeum, H. silacea and Hyalomma spp., but hand dressing and shorter dipping intervals might be necessary to control these ticks in the field. The sheep paralysis tick, I. pilosus, seemed to be resistant to “Gammexane” but was readily killed by arsenic.

Sexual exposure to blood and behavioural risks among STI clinic patients in Cape Town, South Africa

Sexual Health ◽  
2005 ◽  
Vol 2 (2) ◽  
pp. 85 ◽  
Author(s):  
Seth C. Kalichman ◽  
Leickness C. Simbayi
Keyword(s):  
South Africa ◽  
Sexual Intercourse ◽  
Hiv Transmission ◽  
Cape Town ◽  
Vaginal Intercourse ◽  
Sex Partners ◽  
Sexually Transmitted ◽  
Treatment Services ◽  
Rapid Spread ◽  
Background Exposure

Background: Exposure to blood during sexual intercourse is potentially important and yet understudied in HIV transmission. Methods: The study included 415 men and 127 women receiving diagnostic and treatment services at a sexually transmitted infections (STI) clinic in Cape Town, South Africa, who completed anonymous sexual health behaviour surveys. Results: More than 30% of both men and women reported engaging in sexual intercourse involving genital bleeding in the previous 3 months. Individuals who had engaged in sexual intercourse involving blood had significantly greater numbers of sex partners in the previous 3 months (OR = 1.6, 95%, CI = 1.1–2.3), engaged in higher rates of unprotected vaginal intercourse (OR = 1.2, 95%, CI = 1.1–1.2), were significantly more likely to have exchanged sex for money or materials (OR = 3.1, 95%, CI = 1.7–5.5) and were significantly more likely to have experienced condom breaks during intercourse (OR = 1.7, 95%, CI = 1.2–2.4). Conclusions: These findings suggest that exposure to blood during vaginal intercourse is prevalent among STI clinic patients in Cape Town and may be an important contributing factor to the rapid spread of HIV in South Africa.

scholarly journals A cryptic species ofMytilus(Mollusca: Bivalvia) on the west coast of South Africa

1984 ◽  
Vol 2 (1) ◽  
pp. 149-162 ◽  
Author(s):  
W. S. Grant ◽  
M. I. Cherry ◽  
A. T. Lombard
Keyword(s):  
South Africa ◽  
Cryptic Species ◽  
West Coast ◽  
The West

scholarly journals The epidemiology of human immunodeficiency virus in South Africa

2001 ◽  
Vol 356 (1411) ◽  
pp. 1077-1086 ◽  
Author(s):  
Brian G. Williams ◽  
Eleanor Gouws
Keyword(s):  
South Africa ◽  
Human Immunodeficiency Virus ◽  
Circular Migration ◽  
Effective Response ◽  
Local Conditions ◽  
Sexually Transmitted ◽  
Immunodeficiency Virus ◽  
Rapid Spread ◽  
Simplex Virus

We review the epidemiology of human immunodeficiency virus (HIV) in South Africa where the prevalence of HIV infection is among the highest in the world. The epidemic reached South Africa relatively recently but the prevalence of infection has increased rapidly and there are significant differences among provinces. Although few 15–year–old people are infected the prevalence increases rapidly with age thereafter, especially among women. The prevalence of herpes simplex virus type 2 exceeds that of HIV and curable sexually transmitted infections are common. ‘Circular migration’ may help to explain the high rates and rapid spread of HIV in the region. The incidence of tuberculosis has increased dramatically as a result of the HIV epidemic. Antiretroviral therapy for the prevention of vertical transmission has been shown to be effective in local conditions but transmission through breast–feeding remains problematical. While some epidemiological models have been developed, much more needs to be done in this regard in order to plan, coordinate and evaluate an effective response to the epidemic. We conclude by discussing some of the research that is needed and steps that could be taken to reduce the continued spread of the infection.

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