An endangered seahorse selectively chooses an artificial structure
- Claassens, Louw, Booth, Anthony J, Hodgson, Alan N
- Authors: Claassens, Louw , Booth, Anthony J , Hodgson, Alan N
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123718 , vital:35486 , https://doi.10.1007/s10641-018-0732-4
- Description: The development of a residential marina estate within the Knysna estuary, South Africa, introduced Reno mattresses (horizontal wire cages filled with rocks) as a novel habitat for the endangered Knysna seahorse Hippocampus capensis. Consistently high seahorse densities on these artificial structures, despite the availability of seagrass habitat, begged the question of whether this habitat was chosen by the seahorse in preference to natural vegetation. An in situ habitat choice experiment was conducted which focused on the choice made by adult H. capensis between natural vegetation (Zostera capensis) and artificial (Reno mattress) habitat within a choice chamber. Seahorses were significantly more likely to move away from Z. capensis onto a Reno mattress structure or remain on this structure. This study concludes that higher H. capensis densities on Reno mattresses within Thesen Islands Marina are owing to some positive feature of this habitat and the underlying processes responsible for the choice made by this species (additional food, holdfasts, protection) can now be investigated.
- Full Text:
- Date Issued: 2018
- Authors: Claassens, Louw , Booth, Anthony J , Hodgson, Alan N
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123718 , vital:35486 , https://doi.10.1007/s10641-018-0732-4
- Description: The development of a residential marina estate within the Knysna estuary, South Africa, introduced Reno mattresses (horizontal wire cages filled with rocks) as a novel habitat for the endangered Knysna seahorse Hippocampus capensis. Consistently high seahorse densities on these artificial structures, despite the availability of seagrass habitat, begged the question of whether this habitat was chosen by the seahorse in preference to natural vegetation. An in situ habitat choice experiment was conducted which focused on the choice made by adult H. capensis between natural vegetation (Zostera capensis) and artificial (Reno mattress) habitat within a choice chamber. Seahorses were significantly more likely to move away from Z. capensis onto a Reno mattress structure or remain on this structure. This study concludes that higher H. capensis densities on Reno mattresses within Thesen Islands Marina are owing to some positive feature of this habitat and the underlying processes responsible for the choice made by this species (additional food, holdfasts, protection) can now be investigated.
- Full Text:
- Date Issued: 2018
Evidence for protandry in Polydactylus quadrifilis in the Kwanza Estuary, Angola, and its implications for local fisheries
- Butler, Edward C, Childs, Amber-Robyn, Winkler, Alexander C, Milner, Marianne V, Potts, Warren M
- Authors: Butler, Edward C , Childs, Amber-Robyn , Winkler, Alexander C , Milner, Marianne V , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124451 , vital:35614 , https://doi.10.1007/s10641-017-0699-6
- Description: A total of 141 Polydactylus quadrifilis were sampled from the Kwanza Estuary in Angola ranging in size from 436 to 1360 mm fork-length (FL). Of these, 124 were male, six intersex and 11 female. Female fish were significantly longer (mm, FL) and heavier (kg) than males and had significantly higher gonadosomatic indices (GSI’s) than those of males and intersex fish. Transitional (intersex) gonads were delimited, with testicular and ovarian regions separated by connective tissue. The first signs of ovarian tissue appeared on the outer ventral surface of the gonad. A second layer of ovarian tissue was first noticeable at either end of the initial ovarian region and developed back towards the centre of the ventral wall to form a luminal space. Early-stage oocytes were commonly found in the outer area of male regions and residual late-stage spermatids and spermatozoa were found in the luminal space of ovarian regions, suggesting a process of sex change from the outside inwards. A loss of male function was noted with increased ovarian prevalence. Based on this evidence it is suggested that P. quadrifilis in the Kwanza Estuary are protandrous. Owing to the reliance of P. quadrifilis on large highly fecund females for egg production, it is likely that they will be sensitive to fishing practices that target larger individuals within the population.
- Full Text:
- Date Issued: 2018
- Authors: Butler, Edward C , Childs, Amber-Robyn , Winkler, Alexander C , Milner, Marianne V , Potts, Warren M
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124451 , vital:35614 , https://doi.10.1007/s10641-017-0699-6
- Description: A total of 141 Polydactylus quadrifilis were sampled from the Kwanza Estuary in Angola ranging in size from 436 to 1360 mm fork-length (FL). Of these, 124 were male, six intersex and 11 female. Female fish were significantly longer (mm, FL) and heavier (kg) than males and had significantly higher gonadosomatic indices (GSI’s) than those of males and intersex fish. Transitional (intersex) gonads were delimited, with testicular and ovarian regions separated by connective tissue. The first signs of ovarian tissue appeared on the outer ventral surface of the gonad. A second layer of ovarian tissue was first noticeable at either end of the initial ovarian region and developed back towards the centre of the ventral wall to form a luminal space. Early-stage oocytes were commonly found in the outer area of male regions and residual late-stage spermatids and spermatozoa were found in the luminal space of ovarian regions, suggesting a process of sex change from the outside inwards. A loss of male function was noted with increased ovarian prevalence. Based on this evidence it is suggested that P. quadrifilis in the Kwanza Estuary are protandrous. Owing to the reliance of P. quadrifilis on large highly fecund females for egg production, it is likely that they will be sensitive to fishing practices that target larger individuals within the population.
- Full Text:
- Date Issued: 2018
From universal to local: perspectives on cultural landscape heritage in South Africa
- Cocks, Michelle L, Vetter, Susan M, Wiersum, K Freerk
- Authors: Cocks, Michelle L , Vetter, Susan M , Wiersum, K Freerk
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141150 , vital:37948 , https://doi.org/10.1080/13527258.2017.1362573
- Description: The concept of cultural landscapes relates to the multifaceted links between people, place and identity. From a professional perspective, the concept refers to a category of designated conservation areas with specific biocultural heritage values. From a local perspective, it may refer to a landscape that is associated with the provision of a culturally-specific sense of identity and belonging. We explore these two perspectives through a comparative analysis of three cultural landscapes in South Africa, the ‘expert’ designated Mapungubwe Cultural Landscape and the Richtersveld Cultural and Botanical Landscape, and the local associative landscape of emaXhoseni, which is not formally recognised. We propose that a biocultural diversity perspective of heritage not only recognises the inextricable relationship between nature and culture, but it also gives prominence to the beliefs, values and practices of local people, and to strengthening their agency to safeguard their heritage in ways and forms that are relevant to them.
- Full Text:
- Date Issued: 2018
- Authors: Cocks, Michelle L , Vetter, Susan M , Wiersum, K Freerk
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141150 , vital:37948 , https://doi.org/10.1080/13527258.2017.1362573
- Description: The concept of cultural landscapes relates to the multifaceted links between people, place and identity. From a professional perspective, the concept refers to a category of designated conservation areas with specific biocultural heritage values. From a local perspective, it may refer to a landscape that is associated with the provision of a culturally-specific sense of identity and belonging. We explore these two perspectives through a comparative analysis of three cultural landscapes in South Africa, the ‘expert’ designated Mapungubwe Cultural Landscape and the Richtersveld Cultural and Botanical Landscape, and the local associative landscape of emaXhoseni, which is not formally recognised. We propose that a biocultural diversity perspective of heritage not only recognises the inextricable relationship between nature and culture, but it also gives prominence to the beliefs, values and practices of local people, and to strengthening their agency to safeguard their heritage in ways and forms that are relevant to them.
- Full Text:
- Date Issued: 2018
Homology modeling and docking of AahII-Nanobody complexes reveal the epitope binding site on AahII scorpion toxin
- Ksouri, Ayoub, Ghedira, Kais, Abderrazek, Rahma Ben, Shankar, B A Gowri, Benkahla, Alia, Tastan Bishop, Özlem, Bouhaouala-Zahar, Balkis
- Authors: Ksouri, Ayoub , Ghedira, Kais , Abderrazek, Rahma Ben , Shankar, B A Gowri , Benkahla, Alia , Tastan Bishop, Özlem , Bouhaouala-Zahar, Balkis
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124604 , vital:35637 , https://doi.10.1016/j.bbrc.2018.01.036
- Description: Scorpion envenoming and its treatment is a public health problem in many parts of the world due to highly toxic venom polypeptides diffusing rapidly within the body of severely envenomed victims. Recently, 38 AahII-specific Nanobody sequences (Nbs) were retrieved from which the performance of NbAahII10 nanobody candidate, to neutralize the most poisonous venom compound namely AahII acting on sodium channels, was established. Herein, structural computational approach is conducted to elucidate the Nb-AahII interactions that support the biological characteristics, using Nb multiple sequence alignment (MSA) followed by modeling and molecular docking investigations (RosettaAntibody, ZDOCK software tools). Sequence and structural analysis showed two dissimilar residues of NbAahII10 CDR1 (Tyr27 and Tyr29) and an inserted polar residue Ser30 that appear to play an important role. Indeed, CDR3 region of NbAahII10 is characterized by a specific Met104 and two negatively chargedresidues Asp115 and Asp117. Complex dockings reveal that NbAahII17 and NbAahII38 share one common binding site on the surface of the AahII toxin divergent from the NbAahII10 one's. At least, a couple of NbAahII10 e AahII residue interactions (Gln38 e Asn44 and Arg62, His64, respectively) are mainly involved in the toxic AahII binding site. Altogether, this study gives valuable insights in the design and development of next generation of antivenom.
- Full Text:
- Date Issued: 2018
- Authors: Ksouri, Ayoub , Ghedira, Kais , Abderrazek, Rahma Ben , Shankar, B A Gowri , Benkahla, Alia , Tastan Bishop, Özlem , Bouhaouala-Zahar, Balkis
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124604 , vital:35637 , https://doi.10.1016/j.bbrc.2018.01.036
- Description: Scorpion envenoming and its treatment is a public health problem in many parts of the world due to highly toxic venom polypeptides diffusing rapidly within the body of severely envenomed victims. Recently, 38 AahII-specific Nanobody sequences (Nbs) were retrieved from which the performance of NbAahII10 nanobody candidate, to neutralize the most poisonous venom compound namely AahII acting on sodium channels, was established. Herein, structural computational approach is conducted to elucidate the Nb-AahII interactions that support the biological characteristics, using Nb multiple sequence alignment (MSA) followed by modeling and molecular docking investigations (RosettaAntibody, ZDOCK software tools). Sequence and structural analysis showed two dissimilar residues of NbAahII10 CDR1 (Tyr27 and Tyr29) and an inserted polar residue Ser30 that appear to play an important role. Indeed, CDR3 region of NbAahII10 is characterized by a specific Met104 and two negatively chargedresidues Asp115 and Asp117. Complex dockings reveal that NbAahII17 and NbAahII38 share one common binding site on the surface of the AahII toxin divergent from the NbAahII10 one's. At least, a couple of NbAahII10 e AahII residue interactions (Gln38 e Asn44 and Arg62, His64, respectively) are mainly involved in the toxic AahII binding site. Altogether, this study gives valuable insights in the design and development of next generation of antivenom.
- Full Text:
- Date Issued: 2018
HUMA: A platform for the analysis of genetic variation in humans
- Brown, David K, Tastan Bishop, Özlem
- Authors: Brown, David K , Tastan Bishop, Özlem
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124653 , vital:35642 , https://doi.10.1002/humu.23334
- Description: The completion of the human genome project at the beginning of the 21st century, along with the rapid advancement of sequencing technologies thereafter, has resulted in exponential growth of biological data. In genetics, this has given rise to numerous variation databases, created to store and annotate the ever-expanding dataset of known mutations. Usually, these databases focus on variation at the sequence level. Few databases focus on the analysis of variation at the 3D level, that is, mapping, visualizing, and determining the effects of variation in protein structures. Additionally, these Web servers seldom incorporate tools to help analyze these data. Here, we present the Human Mutation Analysis (HUMA) Web server and database. HUMA integrates sequence, structure, variation, and disease data into a single, connected database. A user-friendly interface provides click-based data access and visualization, whereas a RESTfulWebAPI provides programmatic access to the data. Tools have been integrated into HUMA to allow initial analyses to be carried out on the server. Furthermore, users can upload their private variation datasets, which are automatically mapped to public data and can be analyzed using the integrated tools. HUMA is freely accessible at https://huma.rubi.ru.ac.za.
- Full Text:
- Date Issued: 2018
- Authors: Brown, David K , Tastan Bishop, Özlem
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124653 , vital:35642 , https://doi.10.1002/humu.23334
- Description: The completion of the human genome project at the beginning of the 21st century, along with the rapid advancement of sequencing technologies thereafter, has resulted in exponential growth of biological data. In genetics, this has given rise to numerous variation databases, created to store and annotate the ever-expanding dataset of known mutations. Usually, these databases focus on variation at the sequence level. Few databases focus on the analysis of variation at the 3D level, that is, mapping, visualizing, and determining the effects of variation in protein structures. Additionally, these Web servers seldom incorporate tools to help analyze these data. Here, we present the Human Mutation Analysis (HUMA) Web server and database. HUMA integrates sequence, structure, variation, and disease data into a single, connected database. A user-friendly interface provides click-based data access and visualization, whereas a RESTfulWebAPI provides programmatic access to the data. Tools have been integrated into HUMA to allow initial analyses to be carried out on the server. Furthermore, users can upload their private variation datasets, which are automatically mapped to public data and can be analyzed using the integrated tools. HUMA is freely accessible at https://huma.rubi.ru.ac.za.
- Full Text:
- Date Issued: 2018
Integrated genetic and morphological data support eco‐evolutionary divergence of Angolan and South African populations of Diplodus hottentotus
- Gwilliam, Michael P, Winkler, Alexander C, Potts, Warren M, Santos, Carmen V D, Sauer, Warwick H H, Shaw, Paul W, McKeown, Niall J
- Authors: Gwilliam, Michael P , Winkler, Alexander C , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124833 , vital:35702 , https://doi.10.1111/jfb.13582
- Description: The genus Diplodus presents multiple cases of taxonomic conjecture. Among these the D. cervinus complex was previously described as comprising three subspecies that are now regarded as separate species: Diplodus cervinus, Diplodus hottentotus and Diplodus omanensis. Diplodus hottentotus exhibits a clear break in its distribution around the Benguela Current system, prompting speculation that Angolan and South African populations flanking this area may be isolated and warrant formal taxonomic distinction. This study reports the first integrated genetic [mitochondrial (mt)DNA and nuclear microsatellite] and morphological (morphometric, meristic and colouration) study to assess patterns of divergence between populations in the two regions. High levels of cytonuclear divergence between the populations support a prolonged period of genetic isolation, with the sharing of only one mtDNA haplotype (12 haplotypes were fully sorted between regions) attributed to retention of ancestral polymorphism. Fish from the two regions were significantly differentiated at a number of morphometric (69·5%) and meristic (46%) characters. In addition, Angolan and South African fish exhibited reciprocally diagnostic colouration patterns that were more similar to Mediterranean and Indian Ocean congeners, respectively. Based on the congruent genetic and phenotypic diversity we suggest that the use of hottentotus, whether for full species or subspecies status, should be restricted to South African D. cervinus to reflect their status as a distinct species-like unit, while the relationship between Angolan and Atlantic–Mediterranean D. cervinus will require further demo-genetic analysis. This study highlights the utility of integrated genetic and morphological approaches to assess taxonomic diversity within the biogeographically dynamic Benguela Current region.
- Full Text:
- Date Issued: 2018
- Authors: Gwilliam, Michael P , Winkler, Alexander C , Potts, Warren M , Santos, Carmen V D , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124833 , vital:35702 , https://doi.10.1111/jfb.13582
- Description: The genus Diplodus presents multiple cases of taxonomic conjecture. Among these the D. cervinus complex was previously described as comprising three subspecies that are now regarded as separate species: Diplodus cervinus, Diplodus hottentotus and Diplodus omanensis. Diplodus hottentotus exhibits a clear break in its distribution around the Benguela Current system, prompting speculation that Angolan and South African populations flanking this area may be isolated and warrant formal taxonomic distinction. This study reports the first integrated genetic [mitochondrial (mt)DNA and nuclear microsatellite] and morphological (morphometric, meristic and colouration) study to assess patterns of divergence between populations in the two regions. High levels of cytonuclear divergence between the populations support a prolonged period of genetic isolation, with the sharing of only one mtDNA haplotype (12 haplotypes were fully sorted between regions) attributed to retention of ancestral polymorphism. Fish from the two regions were significantly differentiated at a number of morphometric (69·5%) and meristic (46%) characters. In addition, Angolan and South African fish exhibited reciprocally diagnostic colouration patterns that were more similar to Mediterranean and Indian Ocean congeners, respectively. Based on the congruent genetic and phenotypic diversity we suggest that the use of hottentotus, whether for full species or subspecies status, should be restricted to South African D. cervinus to reflect their status as a distinct species-like unit, while the relationship between Angolan and Atlantic–Mediterranean D. cervinus will require further demo-genetic analysis. This study highlights the utility of integrated genetic and morphological approaches to assess taxonomic diversity within the biogeographically dynamic Benguela Current region.
- Full Text:
- Date Issued: 2018
Marine resource management and conservation in the Anthropocene
- Aswani, Shankar, Basurto, Xavier, Ferse, Sebastian, Glaser, Marion, Campbell, Lisa, Cinner, Joshua E, Dalton, Tracey, Jenkins, Lekelia D, Miller, Marc L, Pollnac, Richard, McGill University, Christie, Patrick
- Authors: Aswani, Shankar , Basurto, Xavier , Ferse, Sebastian , Glaser, Marion , Campbell, Lisa , Cinner, Joshua E , Dalton, Tracey , Jenkins, Lekelia D , Miller, Marc L , Pollnac, Richard , McGill University , Christie, Patrick
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124987 , vital:35716 , https://doi.10.1017/S0376892917000431
- Description: Because the Anthropocene by definition is an epoch during which environmental change is largely anthropogenic and driven by social, economic, psychological and political forces, environmental social scientists can effectively analyse human behaviour and knowledge systems in this context. In this subject review, we summarize key ways in which the environmental social sciences can better inform fisheries management policy and practice and marine conservation in the Anthropocene. We argue that environmental social scientists are particularly well positioned to synergize research to fill the gaps between: (1) local behaviours/needs/worldviews and marine resource management and biological conservation concerns; and (2) large-scale drivers of planetary environmental change (globalization, affluence, technological change, etc.) and local cognitive, socioeconomic, cultural and historical processes that shape human behaviour in the marine environment. To illustrate this, we synthesize the roles of various environmental social science disciplines in better understanding the interaction between humans and tropical marine ecosystems in developing nations where issues arising from human–coastal interactions are particularly pronounced. We focus on: (1) the application of the environmental social sciences in marine resource management and conservation; (2) the development of ‘new’ socially equitable marine conservation; (3) repopulating the seascape; (4) incorporating multi-scale dynamics of marine social–ecological systems; and (5) envisioning the future of marine resource management and conservation for producing policies and projects for comprehensive and successful resource management and conservation in the Anthropocene.
- Full Text:
- Date Issued: 2018
- Authors: Aswani, Shankar , Basurto, Xavier , Ferse, Sebastian , Glaser, Marion , Campbell, Lisa , Cinner, Joshua E , Dalton, Tracey , Jenkins, Lekelia D , Miller, Marc L , Pollnac, Richard , McGill University , Christie, Patrick
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124987 , vital:35716 , https://doi.10.1017/S0376892917000431
- Description: Because the Anthropocene by definition is an epoch during which environmental change is largely anthropogenic and driven by social, economic, psychological and political forces, environmental social scientists can effectively analyse human behaviour and knowledge systems in this context. In this subject review, we summarize key ways in which the environmental social sciences can better inform fisheries management policy and practice and marine conservation in the Anthropocene. We argue that environmental social scientists are particularly well positioned to synergize research to fill the gaps between: (1) local behaviours/needs/worldviews and marine resource management and biological conservation concerns; and (2) large-scale drivers of planetary environmental change (globalization, affluence, technological change, etc.) and local cognitive, socioeconomic, cultural and historical processes that shape human behaviour in the marine environment. To illustrate this, we synthesize the roles of various environmental social science disciplines in better understanding the interaction between humans and tropical marine ecosystems in developing nations where issues arising from human–coastal interactions are particularly pronounced. We focus on: (1) the application of the environmental social sciences in marine resource management and conservation; (2) the development of ‘new’ socially equitable marine conservation; (3) repopulating the seascape; (4) incorporating multi-scale dynamics of marine social–ecological systems; and (5) envisioning the future of marine resource management and conservation for producing policies and projects for comprehensive and successful resource management and conservation in the Anthropocene.
- Full Text:
- Date Issued: 2018
On Their Own: women, Urbanization, and the Right to the City in South Africa, by Allison GoebelUbuntu und die Post-Development-Debatte. A review
- Authors: Matthews, Sally
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142169 , vital:38055 , DOI: 10.1080/14616742.2017.1400210
- Description: Allison Goebel's book gives much-needed attention to the experiences of women in South African cities. While there is plenty of literature on the urban experience in South Africa, such literature does not often give much attention to gender. Goebel's book draws on the experiences of poorer women living in informal and township areas in the Msunduzi Municipality in KwaZulu-Natal. Goebel has conducted extensive fieldwork in the area and uses this fieldwork to provide the reader with a sense of South African women's experiences of urban living.
- Full Text:
- Date Issued: 2018
- Authors: Matthews, Sally
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/142169 , vital:38055 , DOI: 10.1080/14616742.2017.1400210
- Description: Allison Goebel's book gives much-needed attention to the experiences of women in South African cities. While there is plenty of literature on the urban experience in South Africa, such literature does not often give much attention to gender. Goebel's book draws on the experiences of poorer women living in informal and township areas in the Msunduzi Municipality in KwaZulu-Natal. Goebel has conducted extensive fieldwork in the area and uses this fieldwork to provide the reader with a sense of South African women's experiences of urban living.
- Full Text:
- Date Issued: 2018
Plant–herbivore–parasitoid interactions in an experimental freshwater tritrophic system: higher trophic levels modify competitive interactions between invasive macrophytes
- Martin, Grant D, Coetzee, Julie A, Compton, Stephen G
- Authors: Martin, Grant D , Coetzee, Julie A , Compton, Stephen G
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125686 , vital:35808 , https://doi.org/10.1007/s10750-017-341
- Description: Natural enemies are known to modify competitive hierarchies among terrestrial plants. Here we examine whether the same applies to freshwatersystems. Lagarosiphon major (Hydrocharitaceae) is a submerged aquatic macrophyte, indigenous to South Africa. Outside its native range, it outcompetes with indigenous submerged species and degrades aquatic habitats. Hydrellia lagarosiphon (Diptera: Ephydridae) is the most abundant and ubiquitous herbivore associated with L. major in South Africa and is a potential biological control agent elsewhere. Chaenusa anervata (Hymenoptera: Braconidae: Alysiinae) is its main parasitoid. We generated an experimental system involving one, two or three trophic levels to monitor variation in the competitive ability of L. major relative to that of Myriophyllum spicatum (Haloragaceae), a second submerged macrophyte that can also be invasive. Using inverse linear models to monitor competition, we found that herbivory by H. lagarosiphon greatly reduced the competitive ability of L. major. Addition of the wasp at typical field densities halved the impact of herbivory and reestablished the competitive advantage of L. major. Our results demonstrate how multitrophic interactions modify relative competitive abilities among aquatic plants, emphasize the significance of higher tropic levels in these systems and illustrate how parasitoids can reduce the effectiveness of insects released as biocontrol agents.
- Full Text:
- Date Issued: 2018
- Authors: Martin, Grant D , Coetzee, Julie A , Compton, Stephen G
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125686 , vital:35808 , https://doi.org/10.1007/s10750-017-341
- Description: Natural enemies are known to modify competitive hierarchies among terrestrial plants. Here we examine whether the same applies to freshwatersystems. Lagarosiphon major (Hydrocharitaceae) is a submerged aquatic macrophyte, indigenous to South Africa. Outside its native range, it outcompetes with indigenous submerged species and degrades aquatic habitats. Hydrellia lagarosiphon (Diptera: Ephydridae) is the most abundant and ubiquitous herbivore associated with L. major in South Africa and is a potential biological control agent elsewhere. Chaenusa anervata (Hymenoptera: Braconidae: Alysiinae) is its main parasitoid. We generated an experimental system involving one, two or three trophic levels to monitor variation in the competitive ability of L. major relative to that of Myriophyllum spicatum (Haloragaceae), a second submerged macrophyte that can also be invasive. Using inverse linear models to monitor competition, we found that herbivory by H. lagarosiphon greatly reduced the competitive ability of L. major. Addition of the wasp at typical field densities halved the impact of herbivory and reestablished the competitive advantage of L. major. Our results demonstrate how multitrophic interactions modify relative competitive abilities among aquatic plants, emphasize the significance of higher tropic levels in these systems and illustrate how parasitoids can reduce the effectiveness of insects released as biocontrol agents.
- Full Text:
- Date Issued: 2018
Spermatophore dimorphism in the chokka squid Loligo reynaudii associated with alternative mating tactics
- Sato, Noriyosi, Iwata, Yoko, Shaw, Paul W, Sauer, Warwick H H
- Authors: Sato, Noriyosi , Iwata, Yoko , Shaw, Paul W , Sauer, Warwick H H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127070 , vital:35952 , https://doi.10.1093/mollus/eyy002
- Description: Chokka squid (Loligo reynaudii) have characteristic alternative mating tactics: ‘consort’ males temporarily pair with and guard a female and transfer spermatophores onto her oviduct opening inside the mantle cavity, whereas ‘sneaker’ males rush towards a mating pair and transfer spermatophores onto the female’s buccal membrane near her sperm storage organ. Differences in mating behaviours and their related sperm-storage sites clearly constrain the fertilization process and can drive dimorphism between consort and sneaker males. The presence and character of male dimorphism has not yet been fully examined in this species, but consort males are commonly much larger than sneaker males. We observed clear dimorphism in spermatangia (the sperm mass ejaculated from the spermatophore), consistently associated with the two alternative sperm storage sites on the female’s body. Observations of spermatophores stored in the Needham’s sac of mature males confirmed that small males produce ‘sneaker-type’ spermatangia whereas larger males produce ‘consort-type’ spermatangia, and no individuals possessed both types. Therefore, by association, the mating tactic adopted (including the sperm deposition site used) by individual males can be determined from observation of their spermatangial type, without requiring direct behavioural observation of mating. This ability to infer information about mating tactic will improve our understanding of the reproductive system and mating dynamics in this species.
- Full Text:
- Date Issued: 2018
- Authors: Sato, Noriyosi , Iwata, Yoko , Shaw, Paul W , Sauer, Warwick H H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/127070 , vital:35952 , https://doi.10.1093/mollus/eyy002
- Description: Chokka squid (Loligo reynaudii) have characteristic alternative mating tactics: ‘consort’ males temporarily pair with and guard a female and transfer spermatophores onto her oviduct opening inside the mantle cavity, whereas ‘sneaker’ males rush towards a mating pair and transfer spermatophores onto the female’s buccal membrane near her sperm storage organ. Differences in mating behaviours and their related sperm-storage sites clearly constrain the fertilization process and can drive dimorphism between consort and sneaker males. The presence and character of male dimorphism has not yet been fully examined in this species, but consort males are commonly much larger than sneaker males. We observed clear dimorphism in spermatangia (the sperm mass ejaculated from the spermatophore), consistently associated with the two alternative sperm storage sites on the female’s body. Observations of spermatophores stored in the Needham’s sac of mature males confirmed that small males produce ‘sneaker-type’ spermatangia whereas larger males produce ‘consort-type’ spermatangia, and no individuals possessed both types. Therefore, by association, the mating tactic adopted (including the sperm deposition site used) by individual males can be determined from observation of their spermatangial type, without requiring direct behavioural observation of mating. This ability to infer information about mating tactic will improve our understanding of the reproductive system and mating dynamics in this species.
- Full Text:
- Date Issued: 2018
The uses of Chrysomya megacephala (Fabricius, 1794)(Diptera: Calliphoridae) in forensic entomology:
- Badenhorst, Rozane, Villet, Martin H
- Authors: Badenhorst, Rozane , Villet, Martin H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140631 , vital:37905 , DOI: 10.1080/20961790.2018.1426136
- Description: Chrysomya megacephala (Fabricius, 1794) occurs on every continent and is closely associated with carrion and decaying material in human environments. Its abilities to find dead bodies and carry pathogens give it a prominence in human affairs that may involve prosecution or litigation, and therefore forensic entomologists. The identification, geographical distribution and biology of the species are reviewed to provide a background for approaches that four branches of forensic entomology (urban, stored-product, medico-criminal and environmental) might take to investigations involving this fly.
- Full Text:
- Date Issued: 2018
- Authors: Badenhorst, Rozane , Villet, Martin H
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140631 , vital:37905 , DOI: 10.1080/20961790.2018.1426136
- Description: Chrysomya megacephala (Fabricius, 1794) occurs on every continent and is closely associated with carrion and decaying material in human environments. Its abilities to find dead bodies and carry pathogens give it a prominence in human affairs that may involve prosecution or litigation, and therefore forensic entomologists. The identification, geographical distribution and biology of the species are reviewed to provide a background for approaches that four branches of forensic entomology (urban, stored-product, medico-criminal and environmental) might take to investigations involving this fly.
- Full Text:
- Date Issued: 2018
Variation in perception of environmental change in nine Solomon Islands communities: implications for securing fairness in community-based adaptation
- Ensor, Jonathan Edward, Abernethy, Kirsten Elizabeth, Hoddy, Eric Timothy, Aswani, Shankar, Albert, Simon, Vaccaro, Ismael, Benedict, Jason Jon, Beare, Douglas James
- Authors: Ensor, Jonathan Edward , Abernethy, Kirsten Elizabeth , Hoddy, Eric Timothy , Aswani, Shankar , Albert, Simon , Vaccaro, Ismael , Benedict, Jason Jon , Beare, Douglas James
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145380 , vital:38433 , DOI: 10.1007/s10113-017-1242-1
- Description: Community-based approaches are pursued in recognition of the need for place-based responses to environmental change that integrate local understandings of risk and vulnerability. Yet the potential for fair adaptation is intimately linked to how variations in perceptions of environmental change and risk are treated. There is, however, little empirical evidence of the extent and nature of variations in risk perception in and between multiple community settings. Here, we rely on data from 231 semi-structured interviews conducted in nine communities in Western Province, Solomon Islands, to statistically model different perceptions of risk and change within and between communities.
- Full Text:
- Date Issued: 2018
- Authors: Ensor, Jonathan Edward , Abernethy, Kirsten Elizabeth , Hoddy, Eric Timothy , Aswani, Shankar , Albert, Simon , Vaccaro, Ismael , Benedict, Jason Jon , Beare, Douglas James
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145380 , vital:38433 , DOI: 10.1007/s10113-017-1242-1
- Description: Community-based approaches are pursued in recognition of the need for place-based responses to environmental change that integrate local understandings of risk and vulnerability. Yet the potential for fair adaptation is intimately linked to how variations in perceptions of environmental change and risk are treated. There is, however, little empirical evidence of the extent and nature of variations in risk perception in and between multiple community settings. Here, we rely on data from 231 semi-structured interviews conducted in nine communities in Western Province, Solomon Islands, to statistically model different perceptions of risk and change within and between communities.
- Full Text:
- Date Issued: 2018
A moderate elevation in [CO 2] results in potential hypervirulence on SABBIErica
- Gallagher, Sean, Hill, Jaclyn M, Murugan, N, Botha, Christiaan E J
- Authors: Gallagher, Sean , Hill, Jaclyn M , Murugan, N , Botha, Christiaan E J
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68835 , vital:29329 , https://doi.org/10.1016/j.sajb.2017.10.010
- Description: The Russian Wheat Aphid (Diuraphis noxia Kurdjumov, 1913) (RWA) is a serious pest of grain crops and is of considerable concern in South Africa, particularly in terms of barley grown specifically for the brewing industry. This paper highlights the effect of a small (50 ppm) increase in [CO2] on the growth rate of the four South African RWA biotypes on the SABBIErica barley cultivar. Controlled environment experiments revealed that the colony growth rate for RWASA4 was significantly lower than SA1 under ambient conditions as well as significantly lower than SA1, SA2 or SA3 under elevated CO2 conditions. The unexpected difference suggested an atypical, non-preferential feeding habit on SABBIErica, for RWASA4. The small RWASA4 colonies inflicted similar morphological damage to the significantly larger RWASA1 – RWASA3 biotype populations — indicative of potential hypervirulence under elevated CO2. The continuous feeding of RWASA biotypes causes damage to the transport system as well as substantial, catastrophic damage to mesophyll chloroplasts as well as mitochondria within the host plant's leaves. The TEM study revealed evidence of sequential/systematic degeneration of chloroplasts and mitochondria with continued aphid feeding, which we suggest is an indication of potential emergent hypervirulence under elevated CO2 conditions.
- Full Text: false
- Date Issued: 2017
- Authors: Gallagher, Sean , Hill, Jaclyn M , Murugan, N , Botha, Christiaan E J
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68835 , vital:29329 , https://doi.org/10.1016/j.sajb.2017.10.010
- Description: The Russian Wheat Aphid (Diuraphis noxia Kurdjumov, 1913) (RWA) is a serious pest of grain crops and is of considerable concern in South Africa, particularly in terms of barley grown specifically for the brewing industry. This paper highlights the effect of a small (50 ppm) increase in [CO2] on the growth rate of the four South African RWA biotypes on the SABBIErica barley cultivar. Controlled environment experiments revealed that the colony growth rate for RWASA4 was significantly lower than SA1 under ambient conditions as well as significantly lower than SA1, SA2 or SA3 under elevated CO2 conditions. The unexpected difference suggested an atypical, non-preferential feeding habit on SABBIErica, for RWASA4. The small RWASA4 colonies inflicted similar morphological damage to the significantly larger RWASA1 – RWASA3 biotype populations — indicative of potential hypervirulence under elevated CO2. The continuous feeding of RWASA biotypes causes damage to the transport system as well as substantial, catastrophic damage to mesophyll chloroplasts as well as mitochondria within the host plant's leaves. The TEM study revealed evidence of sequential/systematic degeneration of chloroplasts and mitochondria with continued aphid feeding, which we suggest is an indication of potential emergent hypervirulence under elevated CO2 conditions.
- Full Text: false
- Date Issued: 2017
Fundal pressure during the second stage of labour
- Hofmeyr, Georges Justus, Vogel, Joshua. P, Cuthbert, Anna, Singata, Mandisa
- Authors: Hofmeyr, Georges Justus , Vogel, Joshua. P , Cuthbert, Anna , Singata, Mandisa
- Date: 03-2017
- Subjects: South Africa Pregnancy Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5766 , vital:44640 , https://DOI:10.1002/14651858.CD006067.pub3
- Description: Background Fundal pressure during the second stage of labour (also known as the 'Kristeller manoeuvre') involves application of manual pressure to the uppermost part of the uterus directed towards the birth canal, in an attempt to assist spontaneous vaginal birth and avoid prolonged second stage orthe need for operative birth. Fundal pressure has also been applied using an inflatable belt. Fundal pressure is widely used, however methods of its use vary widely. Despite strongly held opinions in favour of and against the use of fundal pressure, there is limited evidence regarding its maternal and neonatal benefits and harms. There is a need for objective evaluation of the eGectiveness and safety of fundal pressure in the second stage of labour. Objectives To determine if fundal pressure is eGective in achieving spontaneous vaginal birth, and preventing prolonged second stage or the need for operative birth, and to explore maternal and neonatal adverse eGects related to fundal pressure. Search methods We searched Cochrane Pregnancy and Childbirth's Trials Register (30 November 2016) and reference lists of retrieved studies. Selection criteria Randomised and quasi-randomised controlled trials of fundal pressure (manual or by inflatable belt) versus no fundal pressure in women in the second stage of labour with singleton cephalic presentation. Data collection and analysis Two or more review authors independently assessed potential studies for inclusion and quality. We extracted data using a pre-designed form. We entered data into Review Manager 5 soAware and checked for accuracy. Main results Nine trials are included in this updated review. Five trials (3057 women) compared manual fundal pressure versus no fundal pressure. Four trials (891 women) compared fundal pressure by means of an inflatable belt versus no fundal pressure. It was not possible to blind women and staG to this intervention. We assessed two trials as being at high risk of attrition bias and another at high risk of reporting bias. All other trials were low or unclear for other risk of bias domains. Most of the trials had design limitations. Heterogeneity was high for the majority of outcomes. Manual fundal pressure versus no fundal pressure Manual fundal pressure was not associated with changes in: spontaneous vaginal birth within a specified time (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.71 to 1.28; 120 women; 1 trial; very low-quality evidence), instrumental births (RR 3.28, 95% CI 0.14 to 79.65; 197 women; 1 trial), caesarean births (RR 1.10, 95% CI 0.07 to 17.27; 197 women; 1 trial), operative birth (average RR 0.66, 95% CI 0.12 to 3.55; 317 women; 2 studies; I2 = 43%; Tau2 = 0.71; very low-quality evidence), duration of second stage (mean diGerence (MD) -0.80 minutes, 95% CI -3.66 to 2.06 minutes; 194 women; 1 study; very low-quality evidence), low arterial cord pH in newborn babies (RR 1.07, 95% CI 0.72 to 1.58; 297 women; 2 trials; very low-quality evidence), or Apgar scores less than seven at five minutes (average RR 4.48, 95% CI 0.28 to 71.45; 2759 infants; 4 trials; I2 = 89%; Tau2 = 3.55; very low-quality evidence). More women who received manual fundal pressure had cervical tears than in the control group (RR 4.90, 95% CI 1.09 to 21.98; 295 women; 1 trial). No neonatal deaths occurred in either of the two studies reporting this outcome (very low-quality evidence). No trial reported the outcome severe maternal morbidity or death. Fundal pressure by inflatable belt versus no fundal pressure Fundal pressure by inflatable belt did not reduce the number of women havinginstrumental births (average RR 0.73, 95% CI 0.52 to 1.02; 891 women; 4 trials; I2 = 52%; Tau2 = 0.05) or operative births (average RR 0.62, 95% CI 0.38 to 1.01; 891 women; 4 trials; I2 = 78%; Tau2 = 0.14; very low-quality evidence). Heterogeneity was high for both outcomes. Duration of second stage was reported in two trials, which both showed that inflatable belts shortened duration of labour in nulliparous women (average MD -50.80 minutes, 95% CI -94.85 to -6.74 minutes; 253 women; 2 trials; I2 = 97%; Tau2 = 975.94; very low-quality evidence). No data on this outcome were available for multiparous women. The inflatable belt did not make any diGerence to rates of caesarean births (average RR 0.56, 95% CI 0.14 to 2.26; 891 women; 4 trials; I2 = 70%; Tau2 = 0.98), low arterial cord pHin newborn babies (RR 0.47, 95% CI 0.09 to 2.55; 461 infants; 1 trial; low-quality evidence), or Apgar scores less than seven atfive minutes (RR 4.62, 95% CI 0.22 to 95.68; 500 infants; 1 trial; very low-quality evidence). Third degree perinealtears were increased in the inflatable belt group (RR 15.69, 95% CI 2.10 to 117.02; 500 women; 1 trial). Spontaneous vaginal birth within a specified time, neonatal death, andsevere maternal morbidity or death were not reported in any trial. Authors' conclusions There is insuGicient evidence to draw conclusions on the beneficial or harmful eGects of fundal pressure, either manually or by inflatable belt. Fundal pressure by an inflatable belt during the second stage of labour may shorten duration of second stage for nulliparous women, and lower rates of operative birth. However, existing studies are small and their generalizability is uncertain. There is insuGicient evidence regarding safety for the baby. There is no evidence on the use of fundal pressure in specific clinical settings such as inability of the mother to bear down due to exhaustion or unconsciousness. There is currently insuGicient evidence for the routine use of fundal pressure by any method on women in the second stage of labour. Because of current widespread use of the procedure and the potential for use in settings where other methods of assisted birth are not available, further good quality trials are needed. Further evaluation in other groups of women (such as multiparous women) will also be required. Future research should describe in detail how fundal pressure was applied and consider safety of the unborn baby, perineal outcomes, longer-term maternal and infant outcomes and maternal satisfaction.
- Full Text:
- Date Issued: 03-2017
- Authors: Hofmeyr, Georges Justus , Vogel, Joshua. P , Cuthbert, Anna , Singata, Mandisa
- Date: 03-2017
- Subjects: South Africa Pregnancy Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5766 , vital:44640 , https://DOI:10.1002/14651858.CD006067.pub3
- Description: Background Fundal pressure during the second stage of labour (also known as the 'Kristeller manoeuvre') involves application of manual pressure to the uppermost part of the uterus directed towards the birth canal, in an attempt to assist spontaneous vaginal birth and avoid prolonged second stage orthe need for operative birth. Fundal pressure has also been applied using an inflatable belt. Fundal pressure is widely used, however methods of its use vary widely. Despite strongly held opinions in favour of and against the use of fundal pressure, there is limited evidence regarding its maternal and neonatal benefits and harms. There is a need for objective evaluation of the eGectiveness and safety of fundal pressure in the second stage of labour. Objectives To determine if fundal pressure is eGective in achieving spontaneous vaginal birth, and preventing prolonged second stage or the need for operative birth, and to explore maternal and neonatal adverse eGects related to fundal pressure. Search methods We searched Cochrane Pregnancy and Childbirth's Trials Register (30 November 2016) and reference lists of retrieved studies. Selection criteria Randomised and quasi-randomised controlled trials of fundal pressure (manual or by inflatable belt) versus no fundal pressure in women in the second stage of labour with singleton cephalic presentation. Data collection and analysis Two or more review authors independently assessed potential studies for inclusion and quality. We extracted data using a pre-designed form. We entered data into Review Manager 5 soAware and checked for accuracy. Main results Nine trials are included in this updated review. Five trials (3057 women) compared manual fundal pressure versus no fundal pressure. Four trials (891 women) compared fundal pressure by means of an inflatable belt versus no fundal pressure. It was not possible to blind women and staG to this intervention. We assessed two trials as being at high risk of attrition bias and another at high risk of reporting bias. All other trials were low or unclear for other risk of bias domains. Most of the trials had design limitations. Heterogeneity was high for the majority of outcomes. Manual fundal pressure versus no fundal pressure Manual fundal pressure was not associated with changes in: spontaneous vaginal birth within a specified time (risk ratio (RR) 0.96, 95% confidence interval (CI) 0.71 to 1.28; 120 women; 1 trial; very low-quality evidence), instrumental births (RR 3.28, 95% CI 0.14 to 79.65; 197 women; 1 trial), caesarean births (RR 1.10, 95% CI 0.07 to 17.27; 197 women; 1 trial), operative birth (average RR 0.66, 95% CI 0.12 to 3.55; 317 women; 2 studies; I2 = 43%; Tau2 = 0.71; very low-quality evidence), duration of second stage (mean diGerence (MD) -0.80 minutes, 95% CI -3.66 to 2.06 minutes; 194 women; 1 study; very low-quality evidence), low arterial cord pH in newborn babies (RR 1.07, 95% CI 0.72 to 1.58; 297 women; 2 trials; very low-quality evidence), or Apgar scores less than seven at five minutes (average RR 4.48, 95% CI 0.28 to 71.45; 2759 infants; 4 trials; I2 = 89%; Tau2 = 3.55; very low-quality evidence). More women who received manual fundal pressure had cervical tears than in the control group (RR 4.90, 95% CI 1.09 to 21.98; 295 women; 1 trial). No neonatal deaths occurred in either of the two studies reporting this outcome (very low-quality evidence). No trial reported the outcome severe maternal morbidity or death. Fundal pressure by inflatable belt versus no fundal pressure Fundal pressure by inflatable belt did not reduce the number of women havinginstrumental births (average RR 0.73, 95% CI 0.52 to 1.02; 891 women; 4 trials; I2 = 52%; Tau2 = 0.05) or operative births (average RR 0.62, 95% CI 0.38 to 1.01; 891 women; 4 trials; I2 = 78%; Tau2 = 0.14; very low-quality evidence). Heterogeneity was high for both outcomes. Duration of second stage was reported in two trials, which both showed that inflatable belts shortened duration of labour in nulliparous women (average MD -50.80 minutes, 95% CI -94.85 to -6.74 minutes; 253 women; 2 trials; I2 = 97%; Tau2 = 975.94; very low-quality evidence). No data on this outcome were available for multiparous women. The inflatable belt did not make any diGerence to rates of caesarean births (average RR 0.56, 95% CI 0.14 to 2.26; 891 women; 4 trials; I2 = 70%; Tau2 = 0.98), low arterial cord pHin newborn babies (RR 0.47, 95% CI 0.09 to 2.55; 461 infants; 1 trial; low-quality evidence), or Apgar scores less than seven atfive minutes (RR 4.62, 95% CI 0.22 to 95.68; 500 infants; 1 trial; very low-quality evidence). Third degree perinealtears were increased in the inflatable belt group (RR 15.69, 95% CI 2.10 to 117.02; 500 women; 1 trial). Spontaneous vaginal birth within a specified time, neonatal death, andsevere maternal morbidity or death were not reported in any trial. Authors' conclusions There is insuGicient evidence to draw conclusions on the beneficial or harmful eGects of fundal pressure, either manually or by inflatable belt. Fundal pressure by an inflatable belt during the second stage of labour may shorten duration of second stage for nulliparous women, and lower rates of operative birth. However, existing studies are small and their generalizability is uncertain. There is insuGicient evidence regarding safety for the baby. There is no evidence on the use of fundal pressure in specific clinical settings such as inability of the mother to bear down due to exhaustion or unconsciousness. There is currently insuGicient evidence for the routine use of fundal pressure by any method on women in the second stage of labour. Because of current widespread use of the procedure and the potential for use in settings where other methods of assisted birth are not available, further good quality trials are needed. Further evaluation in other groups of women (such as multiparous women) will also be required. Future research should describe in detail how fundal pressure was applied and consider safety of the unborn baby, perineal outcomes, longer-term maternal and infant outcomes and maternal satisfaction.
- Full Text:
- Date Issued: 03-2017
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