Implantation, orientation and validation of a commercially produced heart-rate logger for use in a perciform teleost fish:
- Muller, Cuen, Childs, Amber-Robyn, Duncan, Murray I, Skeeles, Michael R, James, Nicola C, Van der Walt, Kerry-Ann, Winkler, Alexander C, Potts, Warren M
- Authors: Muller, Cuen , Childs, Amber-Robyn , Duncan, Murray I , Skeeles, Michael R , James, Nicola C , Van der Walt, Kerry-Ann , Winkler, Alexander C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148494 , vital:38744 , doi.org.wam.seals.ac.za/10.1093/conphys/coaa035
- Description: Quantifying how the heart rate of ectothermic organisms responds to environmental conditions (e.g. water temperature) is important information to quantify their sensitivity to environmental change. Heart rate studies have typically been conducted in lab environments where fish are confined. However, commercially available implantable heart rate biologgers provide the opportunity to study free-swimming fish. Our study aimed to determine the applicability of an implantable device, typically used on fusiform-shaped fish (e.g. salmonids), for a perciform fish where morphology and anatomy prevent ventral incisions normally used on fusiform-shaped fish.
- Full Text:
- Date Issued: 2020
- Authors: Muller, Cuen , Childs, Amber-Robyn , Duncan, Murray I , Skeeles, Michael R , James, Nicola C , Van der Walt, Kerry-Ann , Winkler, Alexander C , Potts, Warren M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148494 , vital:38744 , doi.org.wam.seals.ac.za/10.1093/conphys/coaa035
- Description: Quantifying how the heart rate of ectothermic organisms responds to environmental conditions (e.g. water temperature) is important information to quantify their sensitivity to environmental change. Heart rate studies have typically been conducted in lab environments where fish are confined. However, commercially available implantable heart rate biologgers provide the opportunity to study free-swimming fish. Our study aimed to determine the applicability of an implantable device, typically used on fusiform-shaped fish (e.g. salmonids), for a perciform fish where morphology and anatomy prevent ventral incisions normally used on fusiform-shaped fish.
- Full Text:
- Date Issued: 2020
Implementation of access and benefit-sharing measures has consequences for classical biological control of weeds:
- Silvestri, Luciano, Sosa, Alejandro, Mc Kay, Fernando, Vitorino, Marcelo D, Hill, Martin P, Zachariades, Costas, Hight, Stephen, Weyl, Philip S R, Smith, David, Djeddour, Djamila, Mason, Peter G
- Authors: Silvestri, Luciano , Sosa, Alejandro , Mc Kay, Fernando , Vitorino, Marcelo D , Hill, Martin P , Zachariades, Costas , Hight, Stephen , Weyl, Philip S R , Smith, David , Djeddour, Djamila , Mason, Peter G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150285 , vital:38964 , https://link.springer.com/article/10.1007/s10526-019-09988-4
- Description: The Convention on Biological Diversity and the Nagoya Protocol establish that genetic resources shall be accessed only upon the existence of prior informed consent of the country that provides those resources and that benefits arising from their utilization shall be shared. Pursuant to both agreements several countries have adopted regulations on access and benefit-sharing. These regulations have created a challenging obstacle to classical biological control of weeds. This paper reviews the experiences of Argentina, Brazil, South Africa, the USA, Canada and CABI in implementing access and benefit-sharing regulations and the implications these measures have on the effective and efficient access, exchange and utilization of biological control agents.
- Full Text:
- Date Issued: 2020
- Authors: Silvestri, Luciano , Sosa, Alejandro , Mc Kay, Fernando , Vitorino, Marcelo D , Hill, Martin P , Zachariades, Costas , Hight, Stephen , Weyl, Philip S R , Smith, David , Djeddour, Djamila , Mason, Peter G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150285 , vital:38964 , https://link.springer.com/article/10.1007/s10526-019-09988-4
- Description: The Convention on Biological Diversity and the Nagoya Protocol establish that genetic resources shall be accessed only upon the existence of prior informed consent of the country that provides those resources and that benefits arising from their utilization shall be shared. Pursuant to both agreements several countries have adopted regulations on access and benefit-sharing. These regulations have created a challenging obstacle to classical biological control of weeds. This paper reviews the experiences of Argentina, Brazil, South Africa, the USA, Canada and CABI in implementing access and benefit-sharing regulations and the implications these measures have on the effective and efficient access, exchange and utilization of biological control agents.
- Full Text:
- Date Issued: 2020
Implementing active surveillance for TB—The views of managers in a resource limited setting, South Africa
- Febisola I. AjuduaID, Robert J. MashID
- Authors: Febisola I. AjuduaID , Robert J. MashID
- Date: 2020
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/11260/4088 , vital:44022
- Full Text:
- Authors: Febisola I. AjuduaID , Robert J. MashID
- Date: 2020
- Language: English
- Type: article
- Identifier: http://hdl.handle.net/11260/4088 , vital:44022
- Full Text:
Implementing prolonged exposure therapy for PTSD in a context of ongoing adversity: a clinical case study
- Booysen, Duane D, Kagee, Ashraf
- Authors: Booysen, Duane D , Kagee, Ashraf
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149275 , vital:38821 , https://0-doi.org.wam.seals.ac.za/10.1177/1534650120925918
- Description: Obstacles regarding the implementation of empirically supported treatments (ESTs) for mental disorders such as post-traumatic stress disorder (PTSD) still require further investigation. One notable obstacle is whether persons in low- and middle-income countries (LMICs) residing in a context of ongoing adversity would benefit from an EST for PTSD. We reflect on the utility of a brief prolonged exposure intervention at a primary care community-counseling center in South Africa. “Sam,” a 45-year-old, female was assessed at baseline, during treatment, postassessment, and at 3-month follow-up. At the beginning of treatment, Sam had a positive diagnosis for PTSD (PSSI-5 = 55, and cutoff is 23) and at the end of treatment (PSSI-5 = 17), and 3-month follow-up (PSSI-5 = 21), she had a negative diagnosis for PTSD. We reflect on the mediating effects that contextual factors such as gang violence had on the treatment process and the feasibility of implementing ESTs for PTSD in LMICs under conditions of ongoing adversity.
- Full Text:
- Date Issued: 2020
- Authors: Booysen, Duane D , Kagee, Ashraf
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149275 , vital:38821 , https://0-doi.org.wam.seals.ac.za/10.1177/1534650120925918
- Description: Obstacles regarding the implementation of empirically supported treatments (ESTs) for mental disorders such as post-traumatic stress disorder (PTSD) still require further investigation. One notable obstacle is whether persons in low- and middle-income countries (LMICs) residing in a context of ongoing adversity would benefit from an EST for PTSD. We reflect on the utility of a brief prolonged exposure intervention at a primary care community-counseling center in South Africa. “Sam,” a 45-year-old, female was assessed at baseline, during treatment, postassessment, and at 3-month follow-up. At the beginning of treatment, Sam had a positive diagnosis for PTSD (PSSI-5 = 55, and cutoff is 23) and at the end of treatment (PSSI-5 = 17), and 3-month follow-up (PSSI-5 = 21), she had a negative diagnosis for PTSD. We reflect on the mediating effects that contextual factors such as gang violence had on the treatment process and the feasibility of implementing ESTs for PTSD in LMICs under conditions of ongoing adversity.
- Full Text:
- Date Issued: 2020
Improved Stability of Rifampicin in the Presence of Gastric-Resistant Isoniazid Microspheres in Acidic Media
- Mwila, Chiluba, Walker, Roderick B
- Authors: Mwila, Chiluba , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183210 , vital:43929 , xlink:href="https://doi.org/10.3390/pharmaceutics12030234"
- Description: The degradation of rifampicin (RIF) in an acidic medium to form 3-formyl rifamycin SV, a poorly absorbed compound, is accelerated in the presence of isoniazid, contributing to the poor bioavailability of rifampicin. This manuscript presents a novel approach in which isoniazid is formulated into gastric-resistant sustained-release microspheres and RIF into microporous floating sustained-release microspheres to reduce the potential for interaction between RIF and isoniazid (INH) in an acidic environment. Hydroxypropyl methylcellulose acetate succinate and Eudragit® L100 polymers were used for the manufacture of isoniazid-loaded gastric-resistant sustained-release microspheres using an o/o solvent emulsification evaporation approach. Microporous floating sustained-release microspheres for the delivery of rifampicin in the stomach were manufactured using emulsification and a diffusion/evaporation process. The design of experiments was used to evaluate the impact of input variables on predefined responses or quality attributes of the microspheres. The percent degradation of rifampicin following 12 h dissolution testing in 0.1 M HCl pH 1.2 in the presence of isoniazid gastric-resistant sustained-release microspheres was only 4.44%. These results indicate that the degradation of rifampicin in the presence of isoniazid in acidic media can be reduced by encapsulation of both active pharmaceutical ingredients to ensure release in different segments of the gastrointestinal tract, potentially improving the bioavailability of rifampicin.
- Full Text:
- Date Issued: 2020
- Authors: Mwila, Chiluba , Walker, Roderick B
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183210 , vital:43929 , xlink:href="https://doi.org/10.3390/pharmaceutics12030234"
- Description: The degradation of rifampicin (RIF) in an acidic medium to form 3-formyl rifamycin SV, a poorly absorbed compound, is accelerated in the presence of isoniazid, contributing to the poor bioavailability of rifampicin. This manuscript presents a novel approach in which isoniazid is formulated into gastric-resistant sustained-release microspheres and RIF into microporous floating sustained-release microspheres to reduce the potential for interaction between RIF and isoniazid (INH) in an acidic environment. Hydroxypropyl methylcellulose acetate succinate and Eudragit® L100 polymers were used for the manufacture of isoniazid-loaded gastric-resistant sustained-release microspheres using an o/o solvent emulsification evaporation approach. Microporous floating sustained-release microspheres for the delivery of rifampicin in the stomach were manufactured using emulsification and a diffusion/evaporation process. The design of experiments was used to evaluate the impact of input variables on predefined responses or quality attributes of the microspheres. The percent degradation of rifampicin following 12 h dissolution testing in 0.1 M HCl pH 1.2 in the presence of isoniazid gastric-resistant sustained-release microspheres was only 4.44%. These results indicate that the degradation of rifampicin in the presence of isoniazid in acidic media can be reduced by encapsulation of both active pharmaceutical ingredients to ensure release in different segments of the gastrointestinal tract, potentially improving the bioavailability of rifampicin.
- Full Text:
- Date Issued: 2020
In Vitro Release Testing (IVRT) of Topical Hydrocortisone Acetate Creams: a novel approach using positive and negative controls
- Mudyahoto, Nyengeterai Amanda, Rath, Seeprarani, Ramanah, Ashmita, Kanfer, Isadore
- Authors: Mudyahoto, Nyengeterai Amanda , Rath, Seeprarani , Ramanah, Ashmita , Kanfer, Isadore
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149849 , vital:38888 , dx.doi.org/10.14227/DT270120P6
- Description: The objective was to develop and validate an in vitro release testing (IVRT) method to assess the release of hydrocortisone acetate (HCA) from five topical formulations. A marketed generic cream containing 1% HCA was used as the reference product. Vertical diffusion cells (VDCs) were used to assess and compare the release rates of HCA from cream formulations containing 0.5%, 1%, and 1.5% HCA. The study describes a novel approach to test the discriminatory power by including both positive and negative controls to declare pharmaceutical equivalence or inequivalence. The validated method was found to be sensitive, linear, precise, reproducible, robust, and selective for the analysis of HCA from topical cream products. Equivalence or inequivalence was established based on SUPAC-SS acceptance criteria using a 90% CI with limits of 75–133.33%. The IVRT method was shown to have discriminatory ability to appropriately measure significant differences in drug release from various cream formulations. This approach also provides useful information for the future development of acceptable IVRT methods to assess topical dosage forms for local action containing different drugs.
- Full Text:
- Date Issued: 2020
- Authors: Mudyahoto, Nyengeterai Amanda , Rath, Seeprarani , Ramanah, Ashmita , Kanfer, Isadore
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149849 , vital:38888 , dx.doi.org/10.14227/DT270120P6
- Description: The objective was to develop and validate an in vitro release testing (IVRT) method to assess the release of hydrocortisone acetate (HCA) from five topical formulations. A marketed generic cream containing 1% HCA was used as the reference product. Vertical diffusion cells (VDCs) were used to assess and compare the release rates of HCA from cream formulations containing 0.5%, 1%, and 1.5% HCA. The study describes a novel approach to test the discriminatory power by including both positive and negative controls to declare pharmaceutical equivalence or inequivalence. The validated method was found to be sensitive, linear, precise, reproducible, robust, and selective for the analysis of HCA from topical cream products. Equivalence or inequivalence was established based on SUPAC-SS acceptance criteria using a 90% CI with limits of 75–133.33%. The IVRT method was shown to have discriminatory ability to appropriately measure significant differences in drug release from various cream formulations. This approach also provides useful information for the future development of acceptable IVRT methods to assess topical dosage forms for local action containing different drugs.
- Full Text:
- Date Issued: 2020
Incorporating geomorphic knowledge in the management of wetlands in Africa’s drylands: a rapid assessment of the Kafue Wetland
- Lidzhegu, Z, Ellery, William F N, Mantel, Sukhmani
- Authors: Lidzhegu, Z , Ellery, William F N , Mantel, Sukhmani
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157108 , vital:40087 , https://doi.org/10.1007/s13157-019-01172-9
- Description: Limited knowledge of wetland geomorphic processes often results in poor wetland management. This study aims to illustrate the importance of incorporating geomorphic knowledge of wetland origin in their management. The geomorphic origin and dynamics of the Kafue wetland were determined from the analysis of remotely sensed and geological data. The wetland is a remnant of a paleo-lake that was captured by the tributary of the middle Zambezi River. At the point of capture, resistant Muva Group metavolcanic rocks dominate narrow valleys characterised by straight channels. The resistant lithology prevents the lower Kafue River to cut into the wetland thus maintaining wetland conditions upstream. Sedimentation regime through overbank and bed deposits shaped the wetland’s structure, ecological diversity, and hydrological functioning. The operation of the Itezhi-tezhi dam has negatively impacted the wetland’s hydrological and sedimentological regime. The dam starves the system of sediment needed for promoting levee and channel bed aggradation. Regulated discharge with reduced sediment load can lead to channel incision and therefore reduce flood frequency, which may ultimately lead to wetland desiccation.
- Full Text:
- Date Issued: 2020
- Authors: Lidzhegu, Z , Ellery, William F N , Mantel, Sukhmani
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157108 , vital:40087 , https://doi.org/10.1007/s13157-019-01172-9
- Description: Limited knowledge of wetland geomorphic processes often results in poor wetland management. This study aims to illustrate the importance of incorporating geomorphic knowledge of wetland origin in their management. The geomorphic origin and dynamics of the Kafue wetland were determined from the analysis of remotely sensed and geological data. The wetland is a remnant of a paleo-lake that was captured by the tributary of the middle Zambezi River. At the point of capture, resistant Muva Group metavolcanic rocks dominate narrow valleys characterised by straight channels. The resistant lithology prevents the lower Kafue River to cut into the wetland thus maintaining wetland conditions upstream. Sedimentation regime through overbank and bed deposits shaped the wetland’s structure, ecological diversity, and hydrological functioning. The operation of the Itezhi-tezhi dam has negatively impacted the wetland’s hydrological and sedimentological regime. The dam starves the system of sediment needed for promoting levee and channel bed aggradation. Regulated discharge with reduced sediment load can lead to channel incision and therefore reduce flood frequency, which may ultimately lead to wetland desiccation.
- Full Text:
- Date Issued: 2020
Increasing temperatures increase the risk of reproductive failure in a near threatened alpine groundnesting bird, the Cape Rockjumper Chaetops frenatus:
- Oswald, Krista N, Diener, Elizabeth F, Diener, John P, Cunningham, Susan J, Smit, Ben, Lee, Alan T K
- Authors: Oswald, Krista N , Diener, Elizabeth F , Diener, John P , Cunningham, Susan J , Smit, Ben , Lee, Alan T K
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149324 , vital:38825 , https://0-doi.org.wam.seals.ac.za/10.1111/ibi.12846
- Description: A major cause of reproductive failure in birds is nest predation. Predation risk depends on predator type, as predators vary in their ecology and sensory modalities (e.g. visual vs. olfactory). Snakes (generally olfactory predators) are a major nest predator for small birds, with predation strongly associated with higher temperatures. We investigated nest survival in a ground‐nesting alpine species, the Cape Rockjumper Chaetops frenatus , endemic to alpine fynbos in southwestern South Africa. We collected 3 years of nest data, testing whether nest survival was related to (1) habitat stage (early post‐fire vs. late post‐fire habitat, ≤ 3 and > 3 years since fire respectively), (2) nest concealment and (3) temperature. We found that nests had better survival at lower temperatures, with snake predation (our main source of predation) increasing in higher temperatures.
- Full Text:
- Date Issued: 2020
- Authors: Oswald, Krista N , Diener, Elizabeth F , Diener, John P , Cunningham, Susan J , Smit, Ben , Lee, Alan T K
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149324 , vital:38825 , https://0-doi.org.wam.seals.ac.za/10.1111/ibi.12846
- Description: A major cause of reproductive failure in birds is nest predation. Predation risk depends on predator type, as predators vary in their ecology and sensory modalities (e.g. visual vs. olfactory). Snakes (generally olfactory predators) are a major nest predator for small birds, with predation strongly associated with higher temperatures. We investigated nest survival in a ground‐nesting alpine species, the Cape Rockjumper Chaetops frenatus , endemic to alpine fynbos in southwestern South Africa. We collected 3 years of nest data, testing whether nest survival was related to (1) habitat stage (early post‐fire vs. late post‐fire habitat, ≤ 3 and > 3 years since fire respectively), (2) nest concealment and (3) temperature. We found that nests had better survival at lower temperatures, with snake predation (our main source of predation) increasing in higher temperatures.
- Full Text:
- Date Issued: 2020
Influence of intra-and interspecific variation in predator–prey body size ratios on trophic interaction strengths:
- Cuthbert, Ross N, Wasserman, Ryan J, Dalu, Tatenda, Kaiser, Horst, Weyl, Olaf L F, Dick, Jaimie T A, Sentis, Arnaud, McCoy, Michael W, Alexander, Mhairi E
- Authors: Cuthbert, Ross N , Wasserman, Ryan J , Dalu, Tatenda , Kaiser, Horst , Weyl, Olaf L F , Dick, Jaimie T A , Sentis, Arnaud , McCoy, Michael W , Alexander, Mhairi E
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149358 , vital:38839 , https://0-doi.org.wam.seals.ac.za/10.1002/ece3.6332
- Description: Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of interaction strengths. However, studies quantifying the combined influence of intra‐ and interspecific variation in predator–prey body size ratios are lacking. We use a comparative functional response approach to examine interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra‐ and interspecific predator–prey body mass ratios on the scaling of attack rates and handling times.
- Full Text:
- Date Issued: 2020
- Authors: Cuthbert, Ross N , Wasserman, Ryan J , Dalu, Tatenda , Kaiser, Horst , Weyl, Olaf L F , Dick, Jaimie T A , Sentis, Arnaud , McCoy, Michael W , Alexander, Mhairi E
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149358 , vital:38839 , https://0-doi.org.wam.seals.ac.za/10.1002/ece3.6332
- Description: Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of interaction strengths. However, studies quantifying the combined influence of intra‐ and interspecific variation in predator–prey body size ratios are lacking. We use a comparative functional response approach to examine interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra‐ and interspecific predator–prey body mass ratios on the scaling of attack rates and handling times.
- Full Text:
- Date Issued: 2020
Insect herbivores associated with Lycium ferocissimum (Solanaceae) in South Africa and their potential as biological control agents in Australia
- Chari, Lenon D, Mauda, EV, Martin, Grant D, Raghu, S
- Authors: Chari, Lenon D , Mauda, EV , Martin, Grant D , Raghu, S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407035 , vital:70331 , xlink:href="https://hdl.handle.net/10520/EJC-203b8dbc7b"
- Description: Lycium ferocissimum Miers (Solanaceae) is an indigenous shrub in South Africa but has become invasive in several countries including Australia, where chemical and mechanical control methods have proved costly and unsustainable. In Australia, biological control is being considered as a management option, but the herbivorous insects associated with the plant in its native range are not well known. The aim of this study was to survey the phytophagous insects associated with L. ferocissimum in South Africa and prioritise promising biological control agents. In South Africa, the plant occurs in two geographically distinct areas, the Eastern and Western Cape provinces. Surveys for phytophagous insects on L. ferocissimum were carried out repeatedly over a two-year period in these two regions. The number of insect species found in the Eastern Cape Province (55) was higher than that in the WesternCapeProvince (41), but insect diversity based on Shannon indices was highest in the Western Cape Province. Indicator species analysis revealed eight insect herbivore species driving the differences in the herbivore communities between the two provinces. Based on insect distribution, abundance, feeding preference and available literature, three species were prioritised as potential biological control agents. These include the leaf-chewing beetles Cassida distinguenda Spaeth (Chrysomelidae) and Cleta eckloni Mulsant (Coccinellidae) and the leaf-mining weevil Neoplatygaster serietuberculata Gyllenhal (Curculionidae).
- Full Text:
- Date Issued: 2020
- Authors: Chari, Lenon D , Mauda, EV , Martin, Grant D , Raghu, S
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/407035 , vital:70331 , xlink:href="https://hdl.handle.net/10520/EJC-203b8dbc7b"
- Description: Lycium ferocissimum Miers (Solanaceae) is an indigenous shrub in South Africa but has become invasive in several countries including Australia, where chemical and mechanical control methods have proved costly and unsustainable. In Australia, biological control is being considered as a management option, but the herbivorous insects associated with the plant in its native range are not well known. The aim of this study was to survey the phytophagous insects associated with L. ferocissimum in South Africa and prioritise promising biological control agents. In South Africa, the plant occurs in two geographically distinct areas, the Eastern and Western Cape provinces. Surveys for phytophagous insects on L. ferocissimum were carried out repeatedly over a two-year period in these two regions. The number of insect species found in the Eastern Cape Province (55) was higher than that in the WesternCapeProvince (41), but insect diversity based on Shannon indices was highest in the Western Cape Province. Indicator species analysis revealed eight insect herbivore species driving the differences in the herbivore communities between the two provinces. Based on insect distribution, abundance, feeding preference and available literature, three species were prioritised as potential biological control agents. These include the leaf-chewing beetles Cassida distinguenda Spaeth (Chrysomelidae) and Cleta eckloni Mulsant (Coccinellidae) and the leaf-mining weevil Neoplatygaster serietuberculata Gyllenhal (Curculionidae).
- Full Text:
- Date Issued: 2020
Integrated computational approaches and tools for allosteric drug discovery:
- Amamuddy, Olivier S, Veldman, Wade, Manyumwa, Colleen, Khairallah, Afrah, Agajanian, Steve, Oluyemi, Odeyemi, Verkhivker, Gennady M, Tastan Bishop, Özlem
- Authors: Amamuddy, Olivier S , Veldman, Wade , Manyumwa, Colleen , Khairallah, Afrah , Agajanian, Steve , Oluyemi, Odeyemi , Verkhivker, Gennady M , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163012 , vital:41004 , https://doi.org/10.3390/ijms21030847
- Description: Understanding molecular mechanisms underlying the complexity of allosteric regulation in proteins has attracted considerable attention in drug discovery due to the benefits and versatility of allosteric modulators in providing desirable selectivity against protein targets while minimizing toxicity and other side effects. The proliferation of novel computational approaches for predicting ligand–protein interactions and binding using dynamic and network-centric perspectives has led to new insights into allosteric mechanisms and facilitated computer-based discovery of allosteric drugs. Although no absolute method of experimental and in silico allosteric drug/site discovery exists, current methods are still being improved. As such, the critical analysis and integration of established approaches into robust, reproducible, and customizable computational pipelines with experimental feedback could make allosteric drug discovery more efficient and reliable. In this article, we review computational approaches for allosteric drug discovery and discuss how these tools can be utilized to develop consensus workflows for in silico identification of allosteric sites and modulators with some applications to pathogen resistance and precision medicine. The emerging realization that allosteric modulators can exploit distinct regulatory mechanisms and can provide access to targeted modulation of protein activities could open opportunities for probing biological processes and in silico design of drug combinations with improved therapeutic indices and a broad range of activities.
- Full Text:
- Date Issued: 2020
- Authors: Amamuddy, Olivier S , Veldman, Wade , Manyumwa, Colleen , Khairallah, Afrah , Agajanian, Steve , Oluyemi, Odeyemi , Verkhivker, Gennady M , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163012 , vital:41004 , https://doi.org/10.3390/ijms21030847
- Description: Understanding molecular mechanisms underlying the complexity of allosteric regulation in proteins has attracted considerable attention in drug discovery due to the benefits and versatility of allosteric modulators in providing desirable selectivity against protein targets while minimizing toxicity and other side effects. The proliferation of novel computational approaches for predicting ligand–protein interactions and binding using dynamic and network-centric perspectives has led to new insights into allosteric mechanisms and facilitated computer-based discovery of allosteric drugs. Although no absolute method of experimental and in silico allosteric drug/site discovery exists, current methods are still being improved. As such, the critical analysis and integration of established approaches into robust, reproducible, and customizable computational pipelines with experimental feedback could make allosteric drug discovery more efficient and reliable. In this article, we review computational approaches for allosteric drug discovery and discuss how these tools can be utilized to develop consensus workflows for in silico identification of allosteric sites and modulators with some applications to pathogen resistance and precision medicine. The emerging realization that allosteric modulators can exploit distinct regulatory mechanisms and can provide access to targeted modulation of protein activities could open opportunities for probing biological processes and in silico design of drug combinations with improved therapeutic indices and a broad range of activities.
- Full Text:
- Date Issued: 2020
Integrated landscape change analysis of protected areas and their surrounding landscapes: application in the Brazilian Cerrado
- Bellón, Beatriz, Blanco, Julien, de Vos, Alta, de Oliviera Roque, Fabio, Pays, Olivier, Renaud, Pierre-Cyril
- Authors: Bellón, Beatriz , Blanco, Julien , de Vos, Alta , de Oliviera Roque, Fabio , Pays, Olivier , Renaud, Pierre-Cyril
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148681 , vital:38763 , https://doi.org/10.3390/rs12091413
- Description: Remote sensing tools have been long used to monitor landscape dynamics inside and around protected areas. Hereto, scientists have largely relied on land use and land cover (LULC) data to derive indicators for monitoring these dynamics, but these metrics do not capture changes in the state of vegetation surfaces that may compromise the ecological integrity of conservation areas’ landscapes. Here, we introduce a methodology that combines LULC change estimates with three Normalized Difference Vegetation Index-based proxy indicators of vegetation productivity, phenology, and structural change. We illustrate the utility of this methodology through a regional and local analysis of the landscape dynamics in the Cerrado Biome in Brazil in 2001 and 2016. Despite relatively little natural vegetation loss inside core protected areas and their legal buffer zones, the different indicators revealed significant LULC conversions from natural vegetation to farming land, general productivity loss, homogenization of natural forests, significant agricultural expansion, and a general increase in productivity. These results suggest an overall degradation of habitats and intensification of land use in the studied conservation area network, highlighting serious conservation inefficiencies in this region and stressing the importance of integrated landscape change analyses to provide complementary indicators of ecologically-relevant dynamics in these key conservation areas.
- Full Text:
- Date Issued: 2020
- Authors: Bellón, Beatriz , Blanco, Julien , de Vos, Alta , de Oliviera Roque, Fabio , Pays, Olivier , Renaud, Pierre-Cyril
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148681 , vital:38763 , https://doi.org/10.3390/rs12091413
- Description: Remote sensing tools have been long used to monitor landscape dynamics inside and around protected areas. Hereto, scientists have largely relied on land use and land cover (LULC) data to derive indicators for monitoring these dynamics, but these metrics do not capture changes in the state of vegetation surfaces that may compromise the ecological integrity of conservation areas’ landscapes. Here, we introduce a methodology that combines LULC change estimates with three Normalized Difference Vegetation Index-based proxy indicators of vegetation productivity, phenology, and structural change. We illustrate the utility of this methodology through a regional and local analysis of the landscape dynamics in the Cerrado Biome in Brazil in 2001 and 2016. Despite relatively little natural vegetation loss inside core protected areas and their legal buffer zones, the different indicators revealed significant LULC conversions from natural vegetation to farming land, general productivity loss, homogenization of natural forests, significant agricultural expansion, and a general increase in productivity. These results suggest an overall degradation of habitats and intensification of land use in the studied conservation area network, highlighting serious conservation inefficiencies in this region and stressing the importance of integrated landscape change analyses to provide complementary indicators of ecologically-relevant dynamics in these key conservation areas.
- Full Text:
- Date Issued: 2020
Integrating Ecosystem Services and Disservices in Valuing Smallholder Livestock and Poultry Production in Three Villages in South Africa
- Herd-Hoare, Shannon C, Shackleton, Charlie M
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176089 , vital:42659 , https://doi.org/10.1016/j.ufug.2020.126740 , https://doi.org/10.21504/RUR.c.5388515.v1
- Description: This study presents an integrated examination of both the ecosystem services (ES) and ecosystem disservices (EDS) associated with smallholder animal husbandry in rural livelihoods in three villages in southeast South Africa. It recognises the contribution of ES supporting and resulting from smallholder livestock and poultry production, but also details the limiting factors or EDS, such as tick-borne disease, birds of prey or unpalatable rangeland, produced by the same system. Using a mixed-methods approach, including focus group discussions with various Participatory Learning and Action (PLA) activities, key informant interviews, household surveys and land-use change mapping on GIS, we consider the relative value and benefits from ES after the effects of EDS, as well as the management and strategies that households adopt to minimise EDS.
- Full Text:
- Date Issued: 2020
- Authors: Herd-Hoare, Shannon C , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176089 , vital:42659 , https://doi.org/10.1016/j.ufug.2020.126740 , https://doi.org/10.21504/RUR.c.5388515.v1
- Description: This study presents an integrated examination of both the ecosystem services (ES) and ecosystem disservices (EDS) associated with smallholder animal husbandry in rural livelihoods in three villages in southeast South Africa. It recognises the contribution of ES supporting and resulting from smallholder livestock and poultry production, but also details the limiting factors or EDS, such as tick-borne disease, birds of prey or unpalatable rangeland, produced by the same system. Using a mixed-methods approach, including focus group discussions with various Participatory Learning and Action (PLA) activities, key informant interviews, household surveys and land-use change mapping on GIS, we consider the relative value and benefits from ES after the effects of EDS, as well as the management and strategies that households adopt to minimise EDS.
- Full Text:
- Date Issued: 2020
Integrating livelihoods and forest conservation through beekeeping in northern KwaZulu-Natal:
- Ricketts, K, Shackleton, Charlie M
- Authors: Ricketts, K , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176358 , vital:42687 , https://doi.org/10.1080/0376835X.2019.1698408
- Description: South Africa has potential to export honey products through promoting beekeeping as an income generating opportunity amongst rural communities. Formalised beekeeping may also reduce wild fires initiated by hunters of wild bee hives. This study examined the contribution of the African Honey Bee (AHB) initiative to rural livelihoods and the incidence of forest fires using a mixed methods approach. The initiative increased incomes of newly trained and active beekeepers, although success rates and honey yields were variable. Core challenges included not catching bees, theft and vandalism of hives, insufficient bee forage, drought and pests. Most respondents also perceived an increase in crop size since AHB began, although few attributed this to pollination from the bees. The number of wild fires attributed to honey hunters more than halved after AHB began. Future steps need to reduce the challenges and integrate beekeeping into broader agriculture and forest conservation programmes.
- Full Text:
- Date Issued: 2020
- Authors: Ricketts, K , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176358 , vital:42687 , https://doi.org/10.1080/0376835X.2019.1698408
- Description: South Africa has potential to export honey products through promoting beekeeping as an income generating opportunity amongst rural communities. Formalised beekeeping may also reduce wild fires initiated by hunters of wild bee hives. This study examined the contribution of the African Honey Bee (AHB) initiative to rural livelihoods and the incidence of forest fires using a mixed methods approach. The initiative increased incomes of newly trained and active beekeepers, although success rates and honey yields were variable. Core challenges included not catching bees, theft and vandalism of hives, insufficient bee forage, drought and pests. Most respondents also perceived an increase in crop size since AHB began, although few attributed this to pollination from the bees. The number of wild fires attributed to honey hunters more than halved after AHB began. Future steps need to reduce the challenges and integrate beekeeping into broader agriculture and forest conservation programmes.
- Full Text:
- Date Issued: 2020
Integrative taxonomy reveals hidden diversity in the southern African darters genus Nannocharax Günther 1867 (Characiformes: Distichodontidae):
- Bragança, Pedro H N, Smith, Timothy G, Vreven, Emmanuel J W M N, Chakona, Albert
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163510 , vital:41044 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163510 , vital:41044 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
Integrative taxonomy reveals hidden diversity in the southern African darters genus Nannocharax Günther 1867 (Characiformes: Distichodontidae):
- Bragança, Pedro H N, Smith, Timothy G, Vreven, Emmanuel J W M N, Chakona, Albert
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163543 , vital:41047 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
- Authors: Bragança, Pedro H N , Smith, Timothy G , Vreven, Emmanuel J W M N , Chakona, Albert
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/163543 , vital:41047 , https://0-doi.org.wam.seals.ac.za/10.1111/jfb.14535
- Description: The present study explored the diversity of Nannocharax within southern Africa by implementing three species delimitation methods for a data set consisting of 37 mitochondrial cytochrome oxidase subunit I sequences. Two unilocus coalescent methods, the General Mixed Yule Coalescent (GMYC) and the Bayesian implementation of the Poisson Tree Processes (bPTP), and a genetic distance method, the Automatic Barcode Gap Discovery (ABGD), were applied. Both GMYC and bPTP delimited the same operational taxonomic units (OTUs), revealing a higher diversity for the genus in the region than previously recognised, whereas the ABGD failed to delimit the same candidate species.
- Full Text:
- Date Issued: 2020
Intraspecific mitochondrial gene variation can be as low as that of nuclear rRNA:
- Matumba, Tshifhiwa G, Oliver, Jody, Barker, Nigel P, McQuaid, Christopher D, Teske, Peter R
- Authors: Matumba, Tshifhiwa G , Oliver, Jody , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160401 , vital:40442 , https://doi.org/10.12688/f1000research.23635.2
- Description: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality.
- Full Text:
- Date Issued: 2020
- Authors: Matumba, Tshifhiwa G , Oliver, Jody , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160401 , vital:40442 , https://doi.org/10.12688/f1000research.23635.2
- Description: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality.
- Full Text:
- Date Issued: 2020
Introduction “New” theory,“post” North-South representations, praxis
- Rodrigues, Cae, Payne, Phillip G, Grange, Lesley L, Carvalho, Isabel C, Steil, Carlos A, Lotz-Sisitka, Heila, Linde-Loubser, Henriette
- Authors: Rodrigues, Cae , Payne, Phillip G , Grange, Lesley L , Carvalho, Isabel C , Steil, Carlos A , Lotz-Sisitka, Heila , Linde-Loubser, Henriette
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182736 , vital:43858 , xlink:href="https://doi.org/10.1080/00958964.2020.1726265"
- Description: At a recent academic conference in the South, nine of us grappled for four days with these “old” questions and their presence within the “new” discourse of “post” environmental education research. We struggled for an additional six-month period of email exchange to see and feel these questions in our own research. That slow, rich, and deeper academic exchange between us culminated in a research agenda, partially (re)presented in a collectively constructed Mindmap (Figure 1), for critiquing the post/new whose framing is described in the remainder of this Introduction to the politics of knowledge production. That politic of slowly and judiciously engaging a collective form of criticism culminates in identifying the research problem, and questions, of this Special Issue (SI) about the role and place of allegedly new theory in the global discourse of allegedly post environmental education research. This specially assembled issue of The Journal of Environmental Education (JEE) is our best effort to (partially) represent a considerable amount of thought about the challenge presented by “post” and “new” Western thought. In translating our collective thought processes to a SI, we anticipate the reflexivity of the field will be critically advanced through engaging a number of emerging debates (Robottom and Hart, 1993) identified in the following pages of this Introduction, and in three “sample” articles specially written by Isabel Carvalho, Carlos Steil and Francisco Abraão Gonzaga, Louise Sund and Karen Pashby, and Phillip Payne, and an “in process” Conclusion written by Cae Rodrigues. There remains much work to do. This SI is only a start of reengaging overdue debates about the post (Hart, 2005).
- Full Text:
- Date Issued: 2020
- Authors: Rodrigues, Cae , Payne, Phillip G , Grange, Lesley L , Carvalho, Isabel C , Steil, Carlos A , Lotz-Sisitka, Heila , Linde-Loubser, Henriette
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182736 , vital:43858 , xlink:href="https://doi.org/10.1080/00958964.2020.1726265"
- Description: At a recent academic conference in the South, nine of us grappled for four days with these “old” questions and their presence within the “new” discourse of “post” environmental education research. We struggled for an additional six-month period of email exchange to see and feel these questions in our own research. That slow, rich, and deeper academic exchange between us culminated in a research agenda, partially (re)presented in a collectively constructed Mindmap (Figure 1), for critiquing the post/new whose framing is described in the remainder of this Introduction to the politics of knowledge production. That politic of slowly and judiciously engaging a collective form of criticism culminates in identifying the research problem, and questions, of this Special Issue (SI) about the role and place of allegedly new theory in the global discourse of allegedly post environmental education research. This specially assembled issue of The Journal of Environmental Education (JEE) is our best effort to (partially) represent a considerable amount of thought about the challenge presented by “post” and “new” Western thought. In translating our collective thought processes to a SI, we anticipate the reflexivity of the field will be critically advanced through engaging a number of emerging debates (Robottom and Hart, 1993) identified in the following pages of this Introduction, and in three “sample” articles specially written by Isabel Carvalho, Carlos Steil and Francisco Abraão Gonzaga, Louise Sund and Karen Pashby, and Phillip Payne, and an “in process” Conclusion written by Cae Rodrigues. There remains much work to do. This SI is only a start of reengaging overdue debates about the post (Hart, 2005).
- Full Text:
- Date Issued: 2020
Investigation of electrocatalytic behaviour of low symmetry cobalt phthalocyanines when clicked to azide grafted carbon electrodes
- Mpeta, Lakethe S, Sen, Pinar, Nyokong, Tebello
- Authors: Mpeta, Lakethe S , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186304 , vital:44483 , xlink:href="https://doi.org/10.1016/j.jelechem.2020.113896"
- Description: This work describes the electrochemical properties of low symmetry cobalt phthalocyanines namely, tris-[(4-tert-butylphenoxy)-4-(pent-4-yn-1-yloxy) phthalocyaniato] cobalt (II) (3) and tris-[(4-tert-butylphenoxy)-4-(4-ethybylbenzyl-oxy) phthalocyaniato] cobalt (II) (5). The complexes were characterized by a number of techniques including UV–Vis, mass, and infrared spectra, as well as elemental analysis. The glassy carbon electrodes were first azide functionalized then clicked to low symmetry phthalocyanines. The click reaction was confirmed using X-ray photoelectron spectra. The constructed electrodes showed excellent electrocatalytic activity towards hydrazine oxidation. Oxidation peaks with low potentials of 0.21 V and 0.26 V, for complexes 3 and 5, respectively were obtained. Complex-5 gave a better detection limit of 0.94 μM and electrocatalytic rate constant of 5.6 × 106 M−1 s−1.
- Full Text:
- Date Issued: 2020
- Authors: Mpeta, Lakethe S , Sen, Pinar , Nyokong, Tebello
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186304 , vital:44483 , xlink:href="https://doi.org/10.1016/j.jelechem.2020.113896"
- Description: This work describes the electrochemical properties of low symmetry cobalt phthalocyanines namely, tris-[(4-tert-butylphenoxy)-4-(pent-4-yn-1-yloxy) phthalocyaniato] cobalt (II) (3) and tris-[(4-tert-butylphenoxy)-4-(4-ethybylbenzyl-oxy) phthalocyaniato] cobalt (II) (5). The complexes were characterized by a number of techniques including UV–Vis, mass, and infrared spectra, as well as elemental analysis. The glassy carbon electrodes were first azide functionalized then clicked to low symmetry phthalocyanines. The click reaction was confirmed using X-ray photoelectron spectra. The constructed electrodes showed excellent electrocatalytic activity towards hydrazine oxidation. Oxidation peaks with low potentials of 0.21 V and 0.26 V, for complexes 3 and 5, respectively were obtained. Complex-5 gave a better detection limit of 0.94 μM and electrocatalytic rate constant of 5.6 × 106 M−1 s−1.
- Full Text:
- Date Issued: 2020
Lions do not change rivers: complex African savannas preclude top-down forcing by large carnivores
- Comley, Jessica, Joubert, Christoffel J, Mgqatsa, Nokubonga, Parker, Daniel M
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149215 , vital:38816 , https://doi.org/10.1016/j.jnc.2020.125844
- Description: Trophic cascade theories such as the ‘behaviourally-mediated trophic cascade hypothesis’ (BMTCH), have mainstreamed as ecological tools for conserving biodiversity and restoring ecosystems. The BMTCH relies on indirect negative effects of large carnivores through suppression of mesocarnivore activity and habitat use. Importantly, effects of top carnivores on mesocarnivores varies over time and space, is dependent on the species involved, and local context. In South Africa, there are very few free-ranging carnivores, as populations are often restricted to enclosed reserves. While predator-proof fences reduce human-wildlife conflict, they also influence space use within communities. We used an enclosed reserve with a relatively full complement of carnivores to test the generality of the BMTCH in the African context. Using single-species, multi-season occupancy models we investigated the spatial dynamics of multiple carnivores. We also investigated spatial partitioning by vegetation type and temporal partitioning.
- Full Text:
- Date Issued: 2020
- Authors: Comley, Jessica , Joubert, Christoffel J , Mgqatsa, Nokubonga , Parker, Daniel M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149215 , vital:38816 , https://doi.org/10.1016/j.jnc.2020.125844
- Description: Trophic cascade theories such as the ‘behaviourally-mediated trophic cascade hypothesis’ (BMTCH), have mainstreamed as ecological tools for conserving biodiversity and restoring ecosystems. The BMTCH relies on indirect negative effects of large carnivores through suppression of mesocarnivore activity and habitat use. Importantly, effects of top carnivores on mesocarnivores varies over time and space, is dependent on the species involved, and local context. In South Africa, there are very few free-ranging carnivores, as populations are often restricted to enclosed reserves. While predator-proof fences reduce human-wildlife conflict, they also influence space use within communities. We used an enclosed reserve with a relatively full complement of carnivores to test the generality of the BMTCH in the African context. Using single-species, multi-season occupancy models we investigated the spatial dynamics of multiple carnivores. We also investigated spatial partitioning by vegetation type and temporal partitioning.
- Full Text:
- Date Issued: 2020