https://commons.ru.ac.za/vital/access/manager/Index en-us 5 https://commons.ru.ac.za/vital/access/manager/Repository/vital:904 Wed 22 Jun 2022 12:38:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5100 Wed 12 Oct 2022 11:53:52 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:804 Wed 12 Oct 2022 11:53:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3334 Wed 12 Oct 2022 09:37:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5961 Tue 21 May 2024 08:05:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2917 Tue 15 Aug 2023 16:14:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2755 Tue 15 Aug 2023 15:50:23 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5607 Tue 15 Aug 2023 10:51:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2847 Thu 13 May 2021 13:03:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3733 Thu 13 May 2021 12:37:24 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3884 Thu 13 May 2021 08:52:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:906 Thu 13 May 2021 08:49:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4739 Thu 13 May 2021 08:48:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:802 Thu 13 May 2021 08:25:50 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1152 Thu 13 May 2021 08:21:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3886 20% of its initial activity after 9 consecutive reuse cycles. When exposed to fixed concentrations of carbofuran or demeton-S-methyl sulfone, immobilised acetylcholinesterase showed similar inhibition characteristics to that of the free enzyme. The decrease in enzyme activity observed after immobilisation to the nanofibres may have been due to several reasons which include some enzyme molecules being immobilised in structural conformations which reduced substrate access to the catalytic site, participation of the catalytic residues in immobilisation and enzyme denaturation due to the reaction conditions used for acetylcholinesterase immobilisation. Similar observations have been widely reported in literature and this is one of the major drawbacks of enzyme immobilisation. In conclusion, nylon-6:chitosan electrospun nanofibres were shown to be suitable supports for facile acetylcholinesterase immobilisation and the immobilised enzyme has potential for use in pesticide detection. Future recommendations for this study include a comparative study of the GA cross-linking method for AChE immobilisation which will lead to more intensely bound enzyme molecules to prevent non-specific binding. An investigation into the effect of inhibitors on stored immobilised AChE, as well as reactivation and reuse studies, may also be useful for determining the cost-effectiveness of reusing immobilised AChE for pesticide detection in environmental water samples. Several models have been designed for the determination of the kinetic parameters for immobilised enzymes. These take into account the mass transfer resistance as well as the overall charge of the immobilisation matrix. The use of these models to analyse experimental data will give a clear understanding of the effects of immobilisation on enzyme activity]]> Thu 13 May 2021 08:19:14 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4740 Thu 13 May 2021 08:16:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:894 Thu 13 May 2021 08:15:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5398 Thu 13 May 2021 08:09:04 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2390 Thu 13 May 2021 08:05:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4727 Thu 13 May 2021 07:40:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3609 Thu 13 May 2021 07:37:16 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4287 0.99. In the column experiment the highest loading capacity of Pt and Pd were 7.4 mg/g and 4.3 mg/g respectively on the nanofiber sorbent material based on ethylenediamine (EDA). The polystyrene and silica-based resins with triethylenetetramine (TETA) functionality (M-TETA and S-TETA) showed selectivity for platinum and palladium, respectively. Metal chlorido complexes loaded on the sorbent materials were recovered by using 3% m/v thiourea solution as teh eluting agent with quantitative desorption efficiency under the selected experimental conditions. The separation of platinum from palladium was partially achieved by selective stripping of PtCl₆²⁻ with 0.5 M of NaClO₄ in 1.0 M HCI with PdCl₄²⁻ was eluted with 0.5 M thiourea in 1.0 M HCI. The selectivity of the M-TETA and S-TETA sorbent materials was proved by column separation of platinum(IV) and palladium(II), respectively, from synthetic solutions containing iridium(IV) and rhodium(III). The loading capacity for platinum on M-TETA was 0.09 mg/g while it was 0.27 mg/g for palladium on S-TETA.]]> Thu 13 May 2021 07:36:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:836 Thu 13 May 2021 07:36:04 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1827 Thu 13 May 2021 07:30:29 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1388 Thu 13 May 2021 07:26:49 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1890 Thu 13 May 2021 07:26:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3559 Thu 13 May 2021 07:24:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1905 Thu 13 May 2021 07:04:56 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3412 Thu 13 May 2021 07:03:22 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1150 Thu 13 May 2021 06:56:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:6044 Thu 13 May 2021 06:55:18 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:874 Thu 13 May 2021 06:49:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:716 Thu 13 May 2021 06:43:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4159 Thu 13 May 2021 06:40:48 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4533 Thu 13 May 2021 06:26:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5199 Thu 13 May 2021 06:23:50 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4703 Thu 13 May 2021 06:20:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1396 Thu 13 May 2021 06:16:57 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5962 Thu 13 May 2021 06:14:33 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3885 Thu 13 May 2021 06:10:45 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:813 Thu 13 May 2021 05:50:38 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2385 Thu 13 May 2021 05:49:18 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3897 Thu 13 May 2021 05:43:16 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1907 Thu 13 May 2021 05:39:31 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1403 Thu 13 May 2021 05:31:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:26598 Thu 13 May 2021 05:29:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4128 Thu 13 May 2021 04:58:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5140 Thu 13 May 2021 04:53:17 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4730 Thu 13 May 2021 04:47:12 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2271 Thu 13 May 2021 04:42:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2756 Thu 13 May 2021 04:39:16 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1404 Thu 13 May 2021 04:24:20 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1384 Thu 13 May 2021 04:16:02 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5178 Thu 13 May 2021 03:56:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3335 Thu 13 May 2021 03:52:41 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:930 Thu 13 May 2021 03:49:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5583 0.05 in all cases). Numerical analyses failed to identify any effect of the sandprawn density on the macrofaunal community structure. The rate of bioturbation was, however, strongly correlated to the sand prawn density. Similarly, the microphytobenthic alga concentrations were significantly negatively correlated to the sand prawn densities ((P < 0.05). The absence of any distinct impact of the sandprawn on the macrobenthic community structure appeared to be related to their low densities in the lower reach of the estuary during the study. To better understand the role of the sandprawn as an ecosystem engineer, a caging experiment was conducted using inclusion and exclusion treatments (n= 5 for each treatment). Densities of the sandprawn in the inclusion treatments (80 ind m⁻²) were in the range of the natural densities within the estuary. The experiment was conducted over a period of 18 weeks in the lower reach of the estuary during summer. The presence of the sandprawn, C kraussi, contributed to a significant decrease in the microphytobenthic algal concentrations and the abundance and biomass of the macrofauna (P < 0.05 in all cases). The decrease in the microphytobenthic algal concentrations in the presence of the sandprawn appeared to be related to the res-suspension of the sediments (bioturbation) generated by the burrowing and feeding activities of the sandprawn. The observed decrease in macrofaunal abundances and biomass in the inclusion treatments appeared to be mediated by both the decreased food availability (mainly the microphytobenthic algae) and the burial of organisms within the sediments. Numerical analysis indicated that the sandprawn did, however, not contribute to a change in the species composition of the macrofauna. Results of the current study indicate that C.kraussi plays an important role in structuring the invertebrate community and energy flow within temporarily/open closed Kasouga Estuary.]]> Thu 13 May 2021 03:41:28 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:805 Thu 13 May 2021 03:39:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1072 Thu 13 May 2021 03:35:49 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2106 Thu 13 May 2021 03:30:08 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1393 Thu 13 May 2021 03:26:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3896 Thu 13 May 2021 03:24:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3554 Thu 13 May 2021 03:23:37 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4179 Thu 13 May 2021 03:02:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1032 Thu 13 May 2021 03:01:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3413 Thu 13 May 2021 02:53:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1412 Thu 13 May 2021 02:50:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:929 Thu 13 May 2021 02:39:03 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3500 Thu 13 May 2021 02:37:51 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5101 Thu 13 May 2021 02:37:27 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:928 Thu 13 May 2021 02:28:55 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1385 Thu 13 May 2021 02:28:33 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5964 Thu 13 May 2021 02:28:11 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5968 Thu 13 May 2021 02:20:58 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5584 0.05 in all cases). Results of the stable isotope study indicated that the mean δ¹³C of the shrimps in the lower, middle and upper reaches were -12.4 (± 1.3) ‰, -15.6 (± 0.5) ‰ and -17.5 (± 0.5) ‰, respectively. The δ¹⁵N isotopes of the shrimps in the lower reach was 11.6 (± 0.5) ‰ with middle and upper reaches having similar δ¹⁵N values, 13.5 (± 0.4) ‰ and 13.4 (± 0.4) ‰, respectively. There was no significant difference in the δ¹³C and δ¹⁵N isotope (p > 0.05) between the sexes of the shrimps. Two-way ANOVA indicated a significant difference in the δ¹³C isotope of the shrimps between the sites (p < 0.05). The difference in the δ¹³C and δ¹⁵N ratios of the shrimps suggests spatial variability in the diet of P. peringueyi within the Kariega Estuary. The diet of the shrimps in the lower reach is primarily composed of Nanozostera capensis epibionts. In the middle reach the diet of the shrimps is likely comprised of the detritus of benthic algae. In the upper reach of the estuary, P. peringueyi likely derives its carbon from a combination of epibionts, benthic algae and detritus derived from Codium.]]> Thu 13 May 2021 02:12:35 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4572 Thu 13 May 2021 02:07:21 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1383 Thu 13 May 2021 02:07:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1053 Thu 13 May 2021 02:06:36 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:796 Thu 13 May 2021 01:58:01 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3890 Thu 13 May 2021 01:56:09 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3132 Thu 13 May 2021 01:55:12 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:718 Thu 13 May 2021 01:54:46 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1051 Thu 13 May 2021 01:46:48 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4291 Thu 13 May 2021 01:46:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:843 Thu 13 May 2021 01:35:54 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1133 Thu 13 May 2021 01:33:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2389 Thu 13 May 2021 01:31:47 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3558 Thu 13 May 2021 01:31:25 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:720 Thu 13 May 2021 01:28:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1401 Thu 13 May 2021 01:27:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:4913 Thu 13 May 2021 01:27:10 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3662 Thu 13 May 2021 01:26:59 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2871 Thu 13 May 2021 01:26:49 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:1397 Thu 06 Jul 2023 12:12:07 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2891 Thu 01 Feb 2024 09:51:00 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2388 Mon 12 Jun 2023 10:15:05 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:2612 Mon 10 Oct 2022 14:28:42 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:3557 Fri 30 Jun 2023 10:03:39 SAST ]]> https://commons.ru.ac.za/vital/access/manager/Repository/vital:5097 Fri 15 Oct 2021 15:17:21 SAST ]]>