The response of the red mangrove Rhizophora mucronata Lam. to salinity and inundation in South Africa

2011 ◽  
Vol 95 (2) ◽  
pp. 71-76 ◽  
Author(s):  
Sabine C.L. Hoppe-Speer ◽  
Janine B. Adams ◽  
Anusha Rajkaran ◽  
Dylan Bailey
Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3844
Author(s):  
Sengodan Karthi ◽  
Karthic Uthirarajan ◽  
Vinothkumar Manohar ◽  
Manigandan Venkatesan ◽  
Kamaraj Chinnaperumal ◽  
...  

The larvicidal potential of crude leaf extracts of Rhizophora mucronata, the red mangrove, using diverse solvent extracts of the plant against the early fourth instar larvae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti mosquito vectors was analyzed. The acetone extract of R. mucronata showed the greatest efficacy: for Cx. quinquefasciatus (LC50 = 0.13 mg/mL; LC90 = 2.84 mg/mL), An. stephensi (LC50 = 0.34 mg/mL; LC90 = 6.03 mg/mL), and Ae. aegypti (LC50 = 0.11 mg/mL; LC90 = 1.35 mg/mL). The acetone extract was further fractionated into four fractions and tested for its larvicidal activity. Fraction 3 showed stronger larvicidal activity against all the three mosquito larvae. Chemical characterization of the acetone extract displayed the existence of several identifiable compounds like phytol, 3,7,11,15-tetramethyl-2-hexadecen-1-ol, 1-hexyl-2-nitrocyclohexane, eicosanoic acid etc. Enzyme assay displayed that R. mucronata active F3-fractions exert divergent effects on all three mosquitos’ biochemical defensive mechanisms. The plant fractions displayed significant repellent activity against all the three mosquito vectors up to the maximum repellent time of 210 min. Thus, the bioactive molecules in the acetone extract of R. murconata leaves showed significant larvicidal and enzyme inhibitory activity and displayed novel eco-friendly tool for mosquito control.


2020 ◽  
Vol 7 (2) ◽  
pp. 210-217
Author(s):  
Omer Mohamed Yousif ◽  
Sumitro Sen

Reintroduction of once existing red mangrove, Rhizophora mucronata trials were carried out in Abu Dhabi, United Arab Emirates. Propagules were procured from Pakistan and cultured in a greenhouse before they were planted alongside existing Avicennia marina forest in two sites of Abu Dhabi emirate, Abu Al Abyad and Ras Ghanada Islands. This study documents the present condition of the plants after 11 years of plantation. Long term survival rate was as high as 81% in Abu Al Abyad while Ras Ghanada experienced a very low survival rate at 10%, primarily due to external factors. In contrast, Ras Ghanada plants showed higher growth with the mean height stands at 2.06 m (SD ± 0.31m), while in Abu Al Abyad it is 1.53 m (SD ± 0.36 m). In Abu Al Abyad, more than one third (36.4%) of surviving plants showed reproductive phenology, whereas in Ras Ghanada it was only 10.3%, despite of greater height classes. Many Rhizophora were also noticed with well-developed stilt roots. This study showed that Rhizophora mucronata can be planted in Abu Dhabi, despite the Emirate's harsh climatic conditions.


1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.


Author(s):  
Alex Johnson ◽  
Amanda Hitchins

Abstract This article summarizes a series of trips sponsored by People to People, a professional exchange program. The trips described in this report were led by the first author of this article and include trips to South Africa, Russia, Vietnam and Cambodia, and Israel. Each of these trips included delegations of 25 to 50 speech-language pathologists and audiologists who participated in professional visits to learn of the health, education, and social conditions in each country. Additionally, opportunities to meet with communication disorders professionals, students, and persons with speech, language, or hearing disabilities were included. People to People, partnered with the American Speech-Language-Hearing Association (ASHA), provides a meaningful and interesting way to learn and travel with colleagues.


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