https://vital.seals.ac.za/vital/access/manager/Index ${session.getAttribute("locale")} 5 https://vital.seals.ac.za/vital/access/manager/Repository/vital:70172 Wed 29 Nov 2023 21:24:48 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45376 Wed 24 Nov 2021 08:42:07 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:56776 Wed 21 Sep 2022 19:37:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50038 Wed 20 Apr 2022 08:42:45 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45301 Wed 17 Nov 2021 14:45:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45300 Wed 17 Nov 2021 14:17:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45292 Wed 17 Nov 2021 10:19:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45287 Wed 17 Nov 2021 09:57:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41028 Wed 12 May 2021 15:08:19 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41159 Wed 12 May 2021 15:05:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41148 Wed 12 May 2021 14:54:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41186 Wed 12 May 2021 14:40:49 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41032 Wed 12 May 2021 14:40:25 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41026 Wed 12 May 2021 14:22:46 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41142 Wed 12 May 2021 14:21:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41029 Wed 12 May 2021 14:19:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41151 Wed 12 May 2021 14:11:42 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41116 Wed 12 May 2021 14:04:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41022 Wed 12 May 2021 14:00:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41010 Wed 12 May 2021 14:00:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41002 Wed 12 May 2021 13:59:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41108 Wed 12 May 2021 13:56:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:41147 Wed 12 May 2021 13:55:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65720 Wed 12 Jul 2023 09:16:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65719 Wed 12 Jul 2023 09:10:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72229 Tue 23 Apr 2024 15:21:07 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72226 Tue 23 Apr 2024 14:46:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72220 Tue 23 Apr 2024 14:10:40 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72208 Tue 23 Apr 2024 11:57:57 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72204 Tue 23 Apr 2024 11:15:30 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:69912 Tue 21 Nov 2023 19:54:50 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:49975 Tue 19 Jul 2022 09:14:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50010 Tue 19 Apr 2022 09:01:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45223 Tue 16 Nov 2021 13:34:06 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70632 Tue 12 Dec 2023 17:50:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45106 99% d.e. for larger alkyl groups. The expected preference for endo-alkylation is supported by NMR (chemical shift, coupling constant and NOE) data and was confirmed by acidic hydrolysis of the pentylated 3-imino lactone to afford the known acid. Computer modelling, with the software package HYPERCHEM®, was used to explore the conformational properties of the alkylated products and their enolate precursors. Exploratory work on the enantiomeric beneficiation of racemic amino acids, using alkylated imino lactone derivatives, revealed preferential exo-protonation of the enolate intermediates. Asymmetric Baylis-Hillman reactions between a novel camphor-derived acrylic ester and a range of aldehydes afforded the corresponding 2-(hydroxyalkyl)acrylates in up to 59% d.e., the observed stereoselectivities being sensitive to both steric and electronic factors. Attempts to prepare imino lactone derivatives from ketopinic acid, although unsuccessful, led to the isolation of two novel W-(carbobenzyloxy)glycinates, whose structures were established by 1- and 2-D NMR spectroscopy. Attempts to prepare "BINAP" analogues from dibomyl ether's also proved unsuccessful, but the investigation led to the discovery of a third, novel dibomyl ether.]]> Tue 09 Nov 2021 15:33:35 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45095 Tue 09 Nov 2021 11:59:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45244 Tue 05 Mar 2024 08:20:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45390 Thu 25 Nov 2021 10:25:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45389 Thu 25 Nov 2021 09:43:32 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50171 Thu 21 Apr 2022 17:26:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50170 Thu 21 Apr 2022 17:19:02 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50169 Thu 21 Apr 2022 17:09:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45326 Thu 18 Nov 2021 15:47:37 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65804 S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-Vis spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO-1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states.]]> Thu 13 Jul 2023 15:22:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65803 Thu 13 Jul 2023 15:14:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65776 Thu 13 Jul 2023 10:47:08 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71945 Thu 04 Apr 2024 20:28:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71939 Thu 04 Apr 2024 19:46:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71930 Thu 04 Apr 2024 18:57:36 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71929 Thu 04 Apr 2024 18:50:26 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71928 Thu 04 Apr 2024 17:34:04 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71927 Thu 04 Apr 2024 17:12:57 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72179 95%) respondents owned livestock while substantially more rural farmers (81%) than urban farmers (35%) engaged in crop production. Drought was perceived by a sizeable proportion (>70%) of small-scale farmers as a very serious environmental challenge with adverse socio-economic repercussions on land-based activities. Livestock losses and crop failure were the key impacts reported by small-scale farmers in both rural and urban settings. About 86% of respondents across the sample reported declines in crop yields, with significantly more farmers in rural sites (45%) than urban sites (31%) reporting so. A substantial proportion of farmers across the sample (93%) reported drought response strategies relating to livestock and crop production, such as changing of farming practices, use of drought-resistant crops and government support, with slight differences in the proportion of farmers reporting so between urban (89 %) and rural (95 %) sites. Concerning government support, most respondents (>70%) stated that they were dissatisfied, with slightly more respondents in urban areas (77%) than in rural (70%) areas reporting so. Overall, the results of this study suggest a minimal response capacity of small-scale farmers to droughts in both rural and urban settings due to socio-economic and administrative factors, which calls for the need for drought-response strategies to build adaptive capacity for small-scale farmers. Turning to close cooperation between different stakeholders, such as local farmers, government officials, practitioners, and scientists might allow co-production of knowledge needed to inform drought response strategies. In some instances, attention needs to be given to farmers who are more vulnerable than others.]]> Sun 21 Apr 2024 09:53:43 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72177 Sun 21 Apr 2024 08:48:55 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72175 Sun 21 Apr 2024 08:14:12 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70536 Sun 10 Dec 2023 13:35:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70535 Sun 10 Dec 2023 13:20:13 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70225 Sun 03 Dec 2023 18:50:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71655 Sat 24 Feb 2024 19:10:47 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71658 Sat 24 Feb 2024 19:06:16 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71649 Sat 24 Feb 2024 16:58:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71647 Sat 24 Feb 2024 16:37:12 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71644 Sat 24 Feb 2024 16:17:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72169 Sat 20 Apr 2024 19:47:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72155 Sat 20 Apr 2024 17:34:11 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72146 Sat 20 Apr 2024 16:17:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72142 Sat 20 Apr 2024 13:15:15 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72141 Sat 20 Apr 2024 13:14:24 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72137 Sat 20 Apr 2024 12:33:12 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72136 Sat 20 Apr 2024 12:25:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72135 Sat 20 Apr 2024 12:19:21 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72133 Sat 20 Apr 2024 12:12:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72132 Sat 20 Apr 2024 11:51:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72131 Sat 20 Apr 2024 11:44:29 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72120 Sat 20 Apr 2024 09:58:35 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71628 Sat 17 Feb 2024 12:46:41 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71626 Sat 17 Feb 2024 11:56:05 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71616 Sat 17 Feb 2024 09:31:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70527 Sat 09 Dec 2023 20:11:22 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70521 Sat 09 Dec 2023 15:34:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70520 Sat 09 Dec 2023 15:27:31 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71963 Sat 06 Apr 2024 14:59:11 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71957 Sat 06 Apr 2024 13:33:28 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:71956 4 and Dst_ -50 nT was used as a criterion for geomagnetic disturbed conditions, while the four geomagnetically quiet days were selected each month based on Kp < 3. Observations of TIDs are made using Global Navigational Satellite Systems (GNSS) total electron content derived data. During quiet conditions, seven and two transhemispheric TIDs were identified over the African-European and American sectors, respectively. The observed TIDs originated from the wintertime hemisphere and propagated into the summertime hemisphere. The horizontal velocity, periods, and horizontal wavelengths of TIDs are in range of cH = 120-274 m/s, 48-80 min and _H = 379-1104 km, respectively. These quiet-time equatorward TIDs have been associated with tertiary gravity waves (GWs) from the dissipation of secondary GWs which are in turn generated from the dissipation of mountain waves (MWs) as a result of excited orographic forcing. The poleward TIDs during geomagnetically quiet conditions over the African and American sectors occur mainly during local daytime. Poleward TIDs were observed mostly in the African-European sector than the American sector. Their horizontal propagation velocities and periods range between 129-280 m/s and 39-70 min over African-European and American sectors. Although the mechanisms responsible for launching quiet-time poleward TIDs have not been established in this study, lower atmospheric processes such as convection systems, sudden stratospheric warming and cold weather fronts may have a role in their generation. During geomagnetic storms in the African sector, almost all poleward TIDs (with the exception of two cases) during the main phase were large-scale with horizontal velocities and periods ranging from 250-503 m/s and 30 min to 2 hours. During recovery phase, poleward TIDs fall under the category of medium scale. In the American sector, the majority of poleward TIDs occurred during the storm's main phase, as opposed to the African-European sector, which experienced a significant number of poleward TIDs during the recovery phase. The periods and horizontal velocities of TIDs range from 45 min-1.5 h and 180-296 m/s during main phase. During the recovery phase, the horizontal velocity and period range from 177-271 m/s and 40-1.5 h, respectively. Overall, it has been shown that statistically, changes in equatorial electrodynamics related to enhanced eastward electric _eld and hence increased equatorial electrojet (vertical E_B drift) correlates highly with the reported poleward TIDs.]]> Sat 06 Apr 2024 13:06:52 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45340 Mon 22 Nov 2021 15:55:03 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65844 Mon 17 Jul 2023 18:43:34 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:65841 Mon 17 Jul 2023 18:08:14 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45264 Mon 15 Nov 2021 15:06:44 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45247 Mon 15 Nov 2021 11:36:45 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45238 Mon 15 Nov 2021 10:55:00 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45075 Mon 08 Nov 2021 09:22:52 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:70302 Mon 04 Dec 2023 18:09:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:50188 Fri 22 Apr 2022 10:25:43 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45335 Fri 19 Nov 2021 14:09:51 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45334 Fri 19 Nov 2021 09:15:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45333 Fri 19 Nov 2021 08:33:53 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:72103 Fri 19 Apr 2024 08:00:09 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45149 Fri 12 Nov 2021 09:37:59 SAST ]]> https://vital.seals.ac.za/vital/access/manager/Repository/vital:45148 Fri 12 Nov 2021 09:27:55 SAST ]]>