Synthesis, characterization and electrochemistry of rhodium (iii) complexes of meso-substituted [14] tribenzotriphyrin (2.1. 1)
- Xue, Zhaoli, Wang, Yemei, Mack, John, Mkhize, Scebi, Nyokong, Tebello, Fang, Yuanyuan, Ou, Zhongping, Kadish, Karl M
- Authors: Xue, Zhaoli , Wang, Yemei , Mack, John , Mkhize, Scebi , Nyokong, Tebello , Fang, Yuanyuan , Ou, Zhongping , Kadish, Karl M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241043 , vital:50899 , xlink:href="https://doi.org/10.1039/C6RA03028A"
- Description: A thermal reaction using a series of [14]tribenzotriphyrins(2.1.1) (TriPs, 1a–d) with Rh2(C8H12)Cl2 provides RhIII–TriP complexes (2a–d) in 40−52% yields. The complexes were characterized by mass spectrometry, UV-visible absorption and 1H NMR spectroscopy. Single crystal X-ray analysis reveals that 2b adopts a dome-shaped conformation. The rhodium(III) ion is coordinated by the three pyrrole nitrogen atoms, two chloride ions and the nitrogen atom of an acetonitrile (CH3CN) solvent molecule. The optical spectra can be assigned using Michl's perimeter model. The L and B bands of the 2a–d complexes lie at ca. 600 and 500 nm, respectively, and are markedly red shifted relative to those of 1a–d. A reversible one-electron oxidation and two reversible one-electron reductions are observed in the cyclic voltammograms of 2a–d in CH2Cl2. The redox potentials are consistent with the optical data and the relatively narrow HOMO–LUMO gaps that are predicted in DFT calculations. TD-DFT calculations have been used to assign a third intense spectral band at 375 nm to a higher energy π → π* transition of the [14]tribenzotriphyrin(2.1.1) π-system.
- Full Text:
- Date Issued: 2016
- Authors: Xue, Zhaoli , Wang, Yemei , Mack, John , Mkhize, Scebi , Nyokong, Tebello , Fang, Yuanyuan , Ou, Zhongping , Kadish, Karl M
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241043 , vital:50899 , xlink:href="https://doi.org/10.1039/C6RA03028A"
- Description: A thermal reaction using a series of [14]tribenzotriphyrins(2.1.1) (TriPs, 1a–d) with Rh2(C8H12)Cl2 provides RhIII–TriP complexes (2a–d) in 40−52% yields. The complexes were characterized by mass spectrometry, UV-visible absorption and 1H NMR spectroscopy. Single crystal X-ray analysis reveals that 2b adopts a dome-shaped conformation. The rhodium(III) ion is coordinated by the three pyrrole nitrogen atoms, two chloride ions and the nitrogen atom of an acetonitrile (CH3CN) solvent molecule. The optical spectra can be assigned using Michl's perimeter model. The L and B bands of the 2a–d complexes lie at ca. 600 and 500 nm, respectively, and are markedly red shifted relative to those of 1a–d. A reversible one-electron oxidation and two reversible one-electron reductions are observed in the cyclic voltammograms of 2a–d in CH2Cl2. The redox potentials are consistent with the optical data and the relatively narrow HOMO–LUMO gaps that are predicted in DFT calculations. TD-DFT calculations have been used to assign a third intense spectral band at 375 nm to a higher energy π → π* transition of the [14]tribenzotriphyrin(2.1.1) π-system.
- Full Text:
- Date Issued: 2016
Synthesis, Characterization, and Electronic Structures of Porphyrins Fused with Polycyclic Aromatic Ring Systems
- Okujima, Tetsuo, Mack, John, Nakamura, Jun, Kubheka, Gugu, Nyokong, Tebello, Zhu, Hua, Komobuchi, Naoki, Ono, Noboru, Yamada, Hiroko, Uno, Hidemitsu, Kobayashi, Nagao
- Authors: Okujima, Tetsuo , Mack, John , Nakamura, Jun , Kubheka, Gugu , Nyokong, Tebello , Zhu, Hua , Komobuchi, Naoki , Ono, Noboru , Yamada, Hiroko , Uno, Hidemitsu , Kobayashi, Nagao
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240360 , vital:50827 , xlink:href="https://doi.org/10.1002/chem.201602213"
- Description: A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro-Diels–Alder reaction of bicyclo[2.2.2]octadiene-fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time-dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier π-molecular orbitals.
- Full Text:
- Date Issued: 2016
- Authors: Okujima, Tetsuo , Mack, John , Nakamura, Jun , Kubheka, Gugu , Nyokong, Tebello , Zhu, Hua , Komobuchi, Naoki , Ono, Noboru , Yamada, Hiroko , Uno, Hidemitsu , Kobayashi, Nagao
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240360 , vital:50827 , xlink:href="https://doi.org/10.1002/chem.201602213"
- Description: A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro-Diels–Alder reaction of bicyclo[2.2.2]octadiene-fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time-dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier π-molecular orbitals.
- Full Text:
- Date Issued: 2016
Teacher code switching consistency and precision in a multilingual mathematics classroom:
- Chikiwa, Clemence, Schäfer, Marc
- Authors: Chikiwa, Clemence , Schäfer, Marc
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141087 , vital:37943 , https://doi.org/10.1080/18117295.2016.1228823
- Description: This paper reports on a study that investigated teacher code switching consistency and precision in multilingual secondary school mathematics classrooms in South Africa. Data was obtained through interviewing and observing five lessons of each of three mathematics teachers purposively selected from three township schools in the Eastern Cape Province. Elements of Gumperz and Mercer’s work on lesson categories and Dowling’s Domains of Mathematical Practice were used to analyse data. Results showed that code switching frequency in general was inconsistent across different lessons for the same teacher.
- Full Text:
- Date Issued: 2016
- Authors: Chikiwa, Clemence , Schäfer, Marc
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141087 , vital:37943 , https://doi.org/10.1080/18117295.2016.1228823
- Description: This paper reports on a study that investigated teacher code switching consistency and precision in multilingual secondary school mathematics classrooms in South Africa. Data was obtained through interviewing and observing five lessons of each of three mathematics teachers purposively selected from three township schools in the Eastern Cape Province. Elements of Gumperz and Mercer’s work on lesson categories and Dowling’s Domains of Mathematical Practice were used to analyse data. Results showed that code switching frequency in general was inconsistent across different lessons for the same teacher.
- Full Text:
- Date Issued: 2016
Teaching and Learning of ‘Water for Agriculture’in Primary Schools in Lesotho, South Africa and Zimbabwe
- Pesanayi, Tichaona V, Mashozhera, Farasten, Khitsane, Lintle
- Authors: Pesanayi, Tichaona V , Mashozhera, Farasten , Khitsane, Lintle
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387289 , vital:68222 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/152741"
- Description: Teaching youths about the subject of water for agriculture is vital in southern Africa where climate adaptation is imperative. Fresh water is a critical natural resource experiencing dangerous scarcity globally, with climate change and variability being key drivers. Agriculture consumes most of the allocated water in most of the southern African countries, so this sector needs particular water harvesting and conservation education. The Food and Agriculture Organisation (FAO) reported that 93% of cultivated land in southern Africa was rain-fed at the beginning of the 21st century. Drought hinders effective agricultural practices in poor-rainfall areas and is a common feature in most southern African countries. Increasingly frequent drought events affect Lesotho, South Africa and Zimbabwe chronically due to climate variability and change. These three countries have school curricula that carry agricultural and sustainability learning to varying extents. Agriculture is taught as a science subject, and tends to be inclined towards normative technicist approaches at the expense of traditional and innovative sustainability practices. This omission in curriculum development and teaching may miss the opportunity to learn from lessons offered by these traditional and innovative systems that have demonstrated resilience to climate variability and change. This paper explores the opportunities and enablers of sustainability learning and relevance in the primary school agriculture curricula of these three countries. The paper argues for inclusion of sustainable agricultural water learning as an act of educational quality and relevance that reflects 21st century socio-ecological, agro-climate and socioeconomic challenges in southern Africa.
- Full Text:
- Date Issued: 2016
- Authors: Pesanayi, Tichaona V , Mashozhera, Farasten , Khitsane, Lintle
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387289 , vital:68222 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/152741"
- Description: Teaching youths about the subject of water for agriculture is vital in southern Africa where climate adaptation is imperative. Fresh water is a critical natural resource experiencing dangerous scarcity globally, with climate change and variability being key drivers. Agriculture consumes most of the allocated water in most of the southern African countries, so this sector needs particular water harvesting and conservation education. The Food and Agriculture Organisation (FAO) reported that 93% of cultivated land in southern Africa was rain-fed at the beginning of the 21st century. Drought hinders effective agricultural practices in poor-rainfall areas and is a common feature in most southern African countries. Increasingly frequent drought events affect Lesotho, South Africa and Zimbabwe chronically due to climate variability and change. These three countries have school curricula that carry agricultural and sustainability learning to varying extents. Agriculture is taught as a science subject, and tends to be inclined towards normative technicist approaches at the expense of traditional and innovative sustainability practices. This omission in curriculum development and teaching may miss the opportunity to learn from lessons offered by these traditional and innovative systems that have demonstrated resilience to climate variability and change. This paper explores the opportunities and enablers of sustainability learning and relevance in the primary school agriculture curricula of these three countries. The paper argues for inclusion of sustainable agricultural water learning as an act of educational quality and relevance that reflects 21st century socio-ecological, agro-climate and socioeconomic challenges in southern Africa.
- Full Text:
- Date Issued: 2016
Technauriture as an Educational Tool in South Africa: translating to read across Africa
- Authors: Kaschula, Russell H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174865 , vital:42516 , https://njas.fi/njas/article/view/109
- Description: This article seeks to situate the importance of orality in southern African communities within the paradigm of Technauriture, that being the intersection of technology, auriture and literature and how it relates to imparting educational messages within South Africa in particular. The process of orality as allowed for through, for example oral histories, music, poetry and story-telling, and how it interacts with the recording process facilitated through modern technology, as well as the return of the oral material via technology in educational and archival circles is further explored in this article. The question which this article seeks to understand is how technology can contribute in the educational milieu.
- Full Text:
- Date Issued: 2016
- Authors: Kaschula, Russell H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/174865 , vital:42516 , https://njas.fi/njas/article/view/109
- Description: This article seeks to situate the importance of orality in southern African communities within the paradigm of Technauriture, that being the intersection of technology, auriture and literature and how it relates to imparting educational messages within South Africa in particular. The process of orality as allowed for through, for example oral histories, music, poetry and story-telling, and how it interacts with the recording process facilitated through modern technology, as well as the return of the oral material via technology in educational and archival circles is further explored in this article. The question which this article seeks to understand is how technology can contribute in the educational milieu.
- Full Text:
- Date Issued: 2016
Temperature-dependence of time-resolved optically stimulated luminescence and composition heterogeneity of synthetic α-Al2O3: C
- Chithambo, Makaiko L, Costin, G
- Authors: Chithambo, Makaiko L , Costin, G
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124172 , vital:35573 , https://doi.org/10.1016/j.jlumin.2016.10.038
- Description: The relationship of pulse-width, lifetime and measurement temperature in describing intensity of time-resolved luminescence optically stimulated at 470 nm from α-Al2O3:C is reported. The change of luminescence intensity with stimulation temperature is discussed in terms of the signal integrated over a complete time-resolved luminescence spectrum or in terms of ratios of the signal emitted either during or after pulsed stimulation to the total signal obtained per spectrum. The temperature-induced change in these parameters depends on whether the pulse-width is less or more than the luminescence lifetime. This is because the lifetime in α-Al2O3:C varies with measurement temperature. We have developed and applied new models to distinguish thermal assistance from different traps and to use this information as an additional means to analyse thermal quenching by using the luminescence intensity integrated from time-resolved spectra. Using a model based on use of the throughput, the activation energy for thermal assistance was determined for the shallow trap as 0.054±0.001 eV and as 0.53±0.03 eV for the main trap. The activation energy for thermal quenching was then evaluated using luminescence yield during the pulse as 1.09±0.01 eV and as 1.12±0.01 eV using the throughput after the pulse. Using the new analytical method based on integrated intensity, the activation energy for thermal quenching was found as 1.00±0.07 eV. These values are self-consistent and show that the methods for analyzing temperature-induced changes in intensity and the attendant thermal effects, such as thermal assistance can be successfully applied. We have also reported a general mathematical model that accounts for the temperature-dependence of time-resolved luminescence from α-Al2O3:C. The luminescence study was complemented by investigation of the phase and composition heterogeneity of the samples.
- Full Text: false
- Date Issued: 2017
- Authors: Chithambo, Makaiko L , Costin, G
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124172 , vital:35573 , https://doi.org/10.1016/j.jlumin.2016.10.038
- Description: The relationship of pulse-width, lifetime and measurement temperature in describing intensity of time-resolved luminescence optically stimulated at 470 nm from α-Al2O3:C is reported. The change of luminescence intensity with stimulation temperature is discussed in terms of the signal integrated over a complete time-resolved luminescence spectrum or in terms of ratios of the signal emitted either during or after pulsed stimulation to the total signal obtained per spectrum. The temperature-induced change in these parameters depends on whether the pulse-width is less or more than the luminescence lifetime. This is because the lifetime in α-Al2O3:C varies with measurement temperature. We have developed and applied new models to distinguish thermal assistance from different traps and to use this information as an additional means to analyse thermal quenching by using the luminescence intensity integrated from time-resolved spectra. Using a model based on use of the throughput, the activation energy for thermal assistance was determined for the shallow trap as 0.054±0.001 eV and as 0.53±0.03 eV for the main trap. The activation energy for thermal quenching was then evaluated using luminescence yield during the pulse as 1.09±0.01 eV and as 1.12±0.01 eV using the throughput after the pulse. Using the new analytical method based on integrated intensity, the activation energy for thermal quenching was found as 1.00±0.07 eV. These values are self-consistent and show that the methods for analyzing temperature-induced changes in intensity and the attendant thermal effects, such as thermal assistance can be successfully applied. We have also reported a general mathematical model that accounts for the temperature-dependence of time-resolved luminescence from α-Al2O3:C. The luminescence study was complemented by investigation of the phase and composition heterogeneity of the samples.
- Full Text: false
- Date Issued: 2017
Temperature-dependent performance and potential distribution of Pareuchaetes insulata, a biological control agent of Chromolaena odorata in South Africa
- Uyi, Osariyekemwen O, Zachariades, Costas, Hill, Martin P, McConnachie, Andrew J
- Authors: Uyi, Osariyekemwen O , Zachariades, Costas , Hill, Martin P , McConnachie, Andrew J
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418067 , vital:71505 , xlink:href="https://doi.org/10.1007/s10526-016-9760-1"
- Description: Despite the release of about 1.9 million individuals of Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae) in KwaZulu-Natal for the biological control of Chromolaena odorata (L.) King and Robinson (Asteraceae) in South Africa, the moth probably only established at one of the 30 release sites and its population level is generally low in the field. To determine whether climate incompatibility in South Africa is responsible for the poor performance of P. insulata, the effects of temperature on life-history traits were investigated under several constant temperatures. Although a degree-day model estimated between 3.9 and 10.0 generations of the moth per year in the weed’s invaded range, survival and fecundity declined while development time was prolonged at constant temperatures below 25 °C, indicating that both direct and indirect negative impacts of low winter temperatures, such as increased mortality, slow development and reduced fecundity as well as exposure to natural enemies, may partly explain the poor performance of P. insulata in South Africa.
- Full Text:
- Date Issued: 2016
- Authors: Uyi, Osariyekemwen O , Zachariades, Costas , Hill, Martin P , McConnachie, Andrew J
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/418067 , vital:71505 , xlink:href="https://doi.org/10.1007/s10526-016-9760-1"
- Description: Despite the release of about 1.9 million individuals of Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae) in KwaZulu-Natal for the biological control of Chromolaena odorata (L.) King and Robinson (Asteraceae) in South Africa, the moth probably only established at one of the 30 release sites and its population level is generally low in the field. To determine whether climate incompatibility in South Africa is responsible for the poor performance of P. insulata, the effects of temperature on life-history traits were investigated under several constant temperatures. Although a degree-day model estimated between 3.9 and 10.0 generations of the moth per year in the weed’s invaded range, survival and fecundity declined while development time was prolonged at constant temperatures below 25 °C, indicating that both direct and indirect negative impacts of low winter temperatures, such as increased mortality, slow development and reduced fecundity as well as exposure to natural enemies, may partly explain the poor performance of P. insulata in South Africa.
- Full Text:
- Date Issued: 2016
The Bero Volcanic Complex: extension of the Paraná-Etendeka Igneous Province into SW Angola
- Marsh, Julian S, Swart, Roger S
- Authors: Marsh, Julian S , Swart, Roger S
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60763 , vital:27827 , https://www.sciencedirect.com/science/article/pii/S0377027316304176
- Description: An extension of the Etendeka-Paraná Igneous Province into SW Angola occurs as minor basalt lavas, intrusive gabbro sheets, minor mafic dykes and thick sheets and lava flows (with minor pyroclastics) of quartz latite composition This suite crops out along the eastern margin of the Cretaceous Namibe Basin in SW Angola. The quartz latites from one locality have been referred to informally as the Giraul volcanics but the name ‘Giraul’ has previously been used for Cretaceous conglomerates. We propose the name Bero Volcanic Complex for this suite of intrusive and extrusive rocks on the basis that the full compositional range of this diverse suite crops out along the Rio Bero. Major and trace element compositions and Sr-, Nd-, and Pb-isotopic compositions indicate that the basalts and gabbros are equivalent to the high-Ti Khumib/Urubici and Pitanga types from the Etendeka and Paraná. The basalts underlie the quartz latites which are cut by mafic dykes some of which are compositionally equivalent to the Paranapanema lavas in the Paraná. Five different geochemical types of high-Ti quartz latite are recognised amongst the silicic volcanics, 3 of which have very close geochemical affinities to the Ventura, Sarusas, and Khoraseb types of the northern Etendeka. Their relative stratigraphic position in the Bero volcanic sequence is the same as in the Etendeka sequence and extend significantly the area over which these types were erupted. The two remaining types, Chinguau and High-Nb are not known from either the Etendeka or the Paraná provinces.
- Full Text:
- Date Issued: 2016
- Authors: Marsh, Julian S , Swart, Roger S
- Date: 2016
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60763 , vital:27827 , https://www.sciencedirect.com/science/article/pii/S0377027316304176
- Description: An extension of the Etendeka-Paraná Igneous Province into SW Angola occurs as minor basalt lavas, intrusive gabbro sheets, minor mafic dykes and thick sheets and lava flows (with minor pyroclastics) of quartz latite composition This suite crops out along the eastern margin of the Cretaceous Namibe Basin in SW Angola. The quartz latites from one locality have been referred to informally as the Giraul volcanics but the name ‘Giraul’ has previously been used for Cretaceous conglomerates. We propose the name Bero Volcanic Complex for this suite of intrusive and extrusive rocks on the basis that the full compositional range of this diverse suite crops out along the Rio Bero. Major and trace element compositions and Sr-, Nd-, and Pb-isotopic compositions indicate that the basalts and gabbros are equivalent to the high-Ti Khumib/Urubici and Pitanga types from the Etendeka and Paraná. The basalts underlie the quartz latites which are cut by mafic dykes some of which are compositionally equivalent to the Paranapanema lavas in the Paraná. Five different geochemical types of high-Ti quartz latite are recognised amongst the silicic volcanics, 3 of which have very close geochemical affinities to the Ventura, Sarusas, and Khoraseb types of the northern Etendeka. Their relative stratigraphic position in the Bero volcanic sequence is the same as in the Etendeka sequence and extend significantly the area over which these types were erupted. The two remaining types, Chinguau and High-Nb are not known from either the Etendeka or the Paraná provinces.
- Full Text:
- Date Issued: 2016
The complex immunological and inflammatory network of adipose tissue in obesity
- Apostolopoulos, Vasso, De Courten, Maximilian P J, Stojanovska, Lily, Blatch, Gregory L, Tangalakis, Kathy, De Courten, Barbora
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
- Authors: Apostolopoulos, Vasso , De Courten, Maximilian P J , Stojanovska, Lily , Blatch, Gregory L , Tangalakis, Kathy , De Courten, Barbora
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66120 , vital:28905 , https://doi.org/10.1002/mnfr.201500272
- Description: publisher version , A number of approaches have been utilized in the prevention, management, and treatment of obesity, including, surgery, medication, diet, exercise, and overall lifestyle changes. Despite these interventions, the prevalence of obesity and the various disorders related to it is growing. In obesity, there is a constant state of chronic low‐grade inflammation which is characterized by activation and infiltration of pro‐inflammatory immune cells and a dysregulated production of high levels of pro‐inflammatory cytokines. This pro‐inflammatory milieu contributes to insulin resistance, type‐2 diabetes, cardiovascular disease, and other related co‐morbidities. The roles of the innate (macrophages, neutrophils, eosinophils, mast cells, NK cells, MAIT cells) and the adaptive (CD4 T cells, CD8 T cells, regulatory T cells, and B cells) immune responses and the roles of adipokines and cytokines in adipose tissue inflammation and obesity are discussed. An understanding of the crosstalk between the immune system and adipocytes may shed light in better treatment modalities for obesity and obesity‐related diseases.
- Full Text: false
- Date Issued: 2016
The development of computational biology in South Africa: successes achieved and lessons learnt
- Mulder, Nicola J, Christoffels, Alan, De Oliveira, Tulio, Gamieldien, Junaid, Hazelhurst, Scott, Joubert, Fourie, Kumuthini, Judit, Pillay, Ché S, Snoep, Jacky L, Tastan Bishop, Özlem, Tiffin, Nicki
- Authors: Mulder, Nicola J , Christoffels, Alan , De Oliveira, Tulio , Gamieldien, Junaid , Hazelhurst, Scott , Joubert, Fourie , Kumuthini, Judit , Pillay, Ché S , Snoep, Jacky L , Tastan Bishop, Özlem , Tiffin, Nicki
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148347 , vital:38731 , DOI: 10.1371/journal.pcbi.1004395
- Description: Bioinformatics is now a critical skill in many research and commercial environments as biological data are increasing in both size and complexity. South African researchers recognized this need in the mid-1990s and responded by working with the government as well as international bodies to develop initiatives to build bioinformatics capacity in the country. Significant injections of support from these bodies provided a springboard for the establishment of computational biology units at multiple universities throughout the country, which took on teaching, basic research and support roles. Several challenges were encountered, for example with unreliability of funding, lack of skills, and lack of infrastructure. However, the bioinformatics community worked together to overcome these, and South Africa is now arguably the leading country in bioinformatics on the African continent. Here we discuss how the discipline developed in the country, highlighting the challenges, successes, and lessons learnt.
- Full Text:
- Date Issued: 2016
- Authors: Mulder, Nicola J , Christoffels, Alan , De Oliveira, Tulio , Gamieldien, Junaid , Hazelhurst, Scott , Joubert, Fourie , Kumuthini, Judit , Pillay, Ché S , Snoep, Jacky L , Tastan Bishop, Özlem , Tiffin, Nicki
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148347 , vital:38731 , DOI: 10.1371/journal.pcbi.1004395
- Description: Bioinformatics is now a critical skill in many research and commercial environments as biological data are increasing in both size and complexity. South African researchers recognized this need in the mid-1990s and responded by working with the government as well as international bodies to develop initiatives to build bioinformatics capacity in the country. Significant injections of support from these bodies provided a springboard for the establishment of computational biology units at multiple universities throughout the country, which took on teaching, basic research and support roles. Several challenges were encountered, for example with unreliability of funding, lack of skills, and lack of infrastructure. However, the bioinformatics community worked together to overcome these, and South Africa is now arguably the leading country in bioinformatics on the African continent. Here we discuss how the discipline developed in the country, highlighting the challenges, successes, and lessons learnt.
- Full Text:
- Date Issued: 2016
The effect of land-use on small mammal diversity inside and outside the Great Fish River Nature Reserve, Eastern Cape, South Africa
- Thondhlana, Gladman, Lagesse, Juliette V
- Authors: Thondhlana, Gladman , Lagesse, Juliette V
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67823 , vital:29150 , https://doi.org/10.1016/j.jaridenv.2016.03.006
- Description: Publisher version , This study investigated small mammal species diversity at 10 paired contrast sites along a fence line inside and outside the Great Fish River Nature Reserve (GFRNR), Eastern Cape, South Africa. The sites outside the GFRNR are used for subsistence land-based activities including livestock production and fuelwood harvesting. From 145 live captures, a total of 114 unique individuals of five small mammal species (four rodents and one elephant shrew) were recorded over 1170 trap nights. Average small mammal species diversity and abundance were significantly higher inside the reserve than outside. Human activities such as livestock grazing seemed to explain low levels of small mammal diversity and abundance at the communal sites. Vegetation variables showed a complex interplay with small mammal diversity. In general, high vegetation diversity had a positive influence on small mammal diversity though the influence of some environmental variables was species-dependent. We conclude that the GFRNR is effective in protecting small mammals but the findings raise questions around the influence of land use practices such as livestock grazing on biodiversity, especially given that local communities in South Africa are continuously seeking greater access to reserves for livestock grazing and other provisioning services.
- Full Text: false
- Date Issued: 2016
- Authors: Thondhlana, Gladman , Lagesse, Juliette V
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67823 , vital:29150 , https://doi.org/10.1016/j.jaridenv.2016.03.006
- Description: Publisher version , This study investigated small mammal species diversity at 10 paired contrast sites along a fence line inside and outside the Great Fish River Nature Reserve (GFRNR), Eastern Cape, South Africa. The sites outside the GFRNR are used for subsistence land-based activities including livestock production and fuelwood harvesting. From 145 live captures, a total of 114 unique individuals of five small mammal species (four rodents and one elephant shrew) were recorded over 1170 trap nights. Average small mammal species diversity and abundance were significantly higher inside the reserve than outside. Human activities such as livestock grazing seemed to explain low levels of small mammal diversity and abundance at the communal sites. Vegetation variables showed a complex interplay with small mammal diversity. In general, high vegetation diversity had a positive influence on small mammal diversity though the influence of some environmental variables was species-dependent. We conclude that the GFRNR is effective in protecting small mammals but the findings raise questions around the influence of land use practices such as livestock grazing on biodiversity, especially given that local communities in South Africa are continuously seeking greater access to reserves for livestock grazing and other provisioning services.
- Full Text: false
- Date Issued: 2016
The effectiveness and impacts of subsidies to film industries
- Collins, Alan, Snowball, Jeanette D
- Authors: Collins, Alan , Snowball, Jeanette D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68511 , vital:29273 , https://www.southafricanculturalobservatory.org.za/
- Description: Publisher version , Conference paper presented at the South African Cultural Observatory, First National Conference: Counting Culture, The Cultural and Creative Industries in National and International Context, 16-17 May 2016, The Boardwalk International Convention Centre, Nelson Mandela Bay.
- Full Text:
- Date Issued: 2016
- Authors: Collins, Alan , Snowball, Jeanette D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68511 , vital:29273 , https://www.southafricanculturalobservatory.org.za/
- Description: Publisher version , Conference paper presented at the South African Cultural Observatory, First National Conference: Counting Culture, The Cultural and Creative Industries in National and International Context, 16-17 May 2016, The Boardwalk International Convention Centre, Nelson Mandela Bay.
- Full Text:
- Date Issued: 2016
The effects of silica based nanoparticles on the photophysicochemical properties, in vitro dark viability and photodynamic therapy study of zinc monocarboxyphenoxy phthalocyanine
- Oluwole, David O, Uddin, Imran, Prinsloo, Earl, Nyokong, Tebello
- Authors: Oluwole, David O , Uddin, Imran , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240371 , vital:50828 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.07.002"
- Description: Aminopropyl triethoxysilane functionalized core SiO2 and core/shell ZnO/SiO2 nanoparticles (NP) were covalently linked to zinc monocarboxyphenoxy phthalocyanine (ZnMCPPc, complex 1) via amide bond formation. The photophysicochemical behavior, in vitro dark viability and photodynamic therapy (PDT) activity against human breast adenocarcinoma cell line (MCF-7 cells) of the conjugates were studied. The nanoconjugates showed enhanced photophysicochemical behavior as compared to complex 1 alone. Complex 1 showed higher dark toxicity against MCF-7 cells when compared to the conjugates. In the dark, complex 1 accounted for less than 50% viable cells at 28.6 μg/mL and 57.1 μg/mL compared to the conjugates which accounted for more than 50% cell viability at these concentrations. The in vitro dark viability and PDT activity of complex 1 was reduced in the presence of these nanoparticles.
- Full Text:
- Date Issued: 2016
- Authors: Oluwole, David O , Uddin, Imran , Prinsloo, Earl , Nyokong, Tebello
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/240371 , vital:50828 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.07.002"
- Description: Aminopropyl triethoxysilane functionalized core SiO2 and core/shell ZnO/SiO2 nanoparticles (NP) were covalently linked to zinc monocarboxyphenoxy phthalocyanine (ZnMCPPc, complex 1) via amide bond formation. The photophysicochemical behavior, in vitro dark viability and photodynamic therapy (PDT) activity against human breast adenocarcinoma cell line (MCF-7 cells) of the conjugates were studied. The nanoconjugates showed enhanced photophysicochemical behavior as compared to complex 1 alone. Complex 1 showed higher dark toxicity against MCF-7 cells when compared to the conjugates. In the dark, complex 1 accounted for less than 50% viable cells at 28.6 μg/mL and 57.1 μg/mL compared to the conjugates which accounted for more than 50% cell viability at these concentrations. The in vitro dark viability and PDT activity of complex 1 was reduced in the presence of these nanoparticles.
- Full Text:
- Date Issued: 2016
The good African society index
- Authors: Botha, Ferdi
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396194 , vital:69157 , xlink:href="https://doi.org/10.1007/s11205-015-0891-z"
- Description: This paper constructs a Good Society Index for 45 African countries, termed the Good African Society Index (GASI). The GASI consists of nine main indexes: (1) economic sustainability, (2) democracy and freedom, (3) child well-being, (4) environment and infrastructure, (5) safety and security, (6) health and health systems, (7) integrity and justice, (8) education, and (9) social sustainability and social cohesion. Each component is split into four sub-components for a total of 36 indicators. Tunisia ranks highest on the GASI, followed by Cape Verde and Botswana. Chad has the lowest GASI score, followed by Central African Republic and Cote d’Ivoire. The GASI is strongly related to the 2012 Human Development Index and Fragile States Index, to a lesser extent, GNI per capita.
- Full Text:
- Date Issued: 2016
- Authors: Botha, Ferdi
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/396194 , vital:69157 , xlink:href="https://doi.org/10.1007/s11205-015-0891-z"
- Description: This paper constructs a Good Society Index for 45 African countries, termed the Good African Society Index (GASI). The GASI consists of nine main indexes: (1) economic sustainability, (2) democracy and freedom, (3) child well-being, (4) environment and infrastructure, (5) safety and security, (6) health and health systems, (7) integrity and justice, (8) education, and (9) social sustainability and social cohesion. Each component is split into four sub-components for a total of 36 indicators. Tunisia ranks highest on the GASI, followed by Cape Verde and Botswana. Chad has the lowest GASI score, followed by Central African Republic and Cote d’Ivoire. The GASI is strongly related to the 2012 Human Development Index and Fragile States Index, to a lesser extent, GNI per capita.
- Full Text:
- Date Issued: 2016
The Guinea pigs of a problem-based learning curriculum
- Reddy, Sarasvathie, McKenna, Sioux
- Authors: Reddy, Sarasvathie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66730 , vital:28987 , ISSN 1470-3300 , https://doi.org/10.1080/14703297.2014.959542
- Description: Publisher version , Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as ‘Guinea pigs’ at the mercy of a curriculum experiment. This article interrogates and problematises the ‘Guinea pig’ identity ascribed to and assumed by the first cohort of students who undertook a PBL curriculum. The article suggests that a range of issues may have come into play in the unfortunate events reported on here, and focuses on the participants’ reported experiences of marginalisation during their clinical education modules in the hospital wards. The impact of power differentials on identity formation was found to be exacerbated by the ‘Guinea pig’ characterisation.
- Full Text: false
- Date Issued: 2016
- Authors: Reddy, Sarasvathie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66730 , vital:28987 , ISSN 1470-3300 , https://doi.org/10.1080/14703297.2014.959542
- Description: Publisher version , Participants in a study on learning the clinical aspects of medicine in a problem-based learning (PBL) curriculum repeatedly referred to themselves as ‘Guinea pigs’ at the mercy of a curriculum experiment. This article interrogates and problematises the ‘Guinea pig’ identity ascribed to and assumed by the first cohort of students who undertook a PBL curriculum. The article suggests that a range of issues may have come into play in the unfortunate events reported on here, and focuses on the participants’ reported experiences of marginalisation during their clinical education modules in the hospital wards. The impact of power differentials on identity formation was found to be exacerbated by the ‘Guinea pig’ characterisation.
- Full Text: false
- Date Issued: 2016
The GULLS project: a comparison of vulnerabilities across selected ocean hotspots and implications for adaptation to global change
- Cochrane, Kevern L, Hobday, Alistair J, Aswani, Shankar, Byfield, Val, Dutra, Leo X, Gasalla, Maria A, Haward, Marcus, Paytan, Adina, Pecl, Gretta T, Popova, Katya, Sainulabdeen, Shyam S, Savage, Candida, Sauer, Warwick H H, van Putten, Ingrid E, Visser, Natascha, TG Team
- Authors: Cochrane, Kevern L , Hobday, Alistair J , Aswani, Shankar , Byfield, Val , Dutra, Leo X , Gasalla, Maria A , Haward, Marcus , Paytan, Adina , Pecl, Gretta T , Popova, Katya , Sainulabdeen, Shyam S , Savage, Candida , Sauer, Warwick H H , van Putten, Ingrid E , Visser, Natascha , TG Team
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422037 , vital:71906
- Description: The GULLS project, `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' has been underway since October 2014. The project has been investigating six regional `hotspots': marine areas experiencing rapid warming. These are south-east Australia, Brazil, India, Solomon Islands, South Africa, and the Mozambique Channel and Madagascar. Rapid warming could be expected to have social, cultural and economic impacts that could affect these countries in different ways and may already be doing so. GULLS has focused on contributing to assessing and reducing the vulnerability of coastal communities and other stakeholders dependent on marine resources and to facilitate adaptation to climate change and variability through an integrated and trans-disciplinary approach. It includes participants from Australia, Brazil, India, Madagascar, New Zealand, South Africa, the United Kingdom and the United States of America. The research programme has been divided into six inter-linked components: ocean models, biological and ecological sensitivity analyses, system models, social vulnerability, policy mapping, and communication and education. This presentation will provide a brief overview of each of these components and describe the benefits that have resulted from the collaborative and transdisciplinary approach of GULLS. Following the standard vulnerability elements of exposure, sensitivity and adaptive capacity, the vulnerabilities of coastal communities and other stakeholders dependent on marine resources in the five hotspots will be compared using a set of indicators derived and populated from results of the research programme. The implications of similarities and differences between the hotspots for adaptation planning and options will be described.
- Full Text:
- Date Issued: 2016
- Authors: Cochrane, Kevern L , Hobday, Alistair J , Aswani, Shankar , Byfield, Val , Dutra, Leo X , Gasalla, Maria A , Haward, Marcus , Paytan, Adina , Pecl, Gretta T , Popova, Katya , Sainulabdeen, Shyam S , Savage, Candida , Sauer, Warwick H H , van Putten, Ingrid E , Visser, Natascha , TG Team
- Date: 2016
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422037 , vital:71906
- Description: The GULLS project, `Global learning for local solutions: Reducing vulnerability of marine-dependent coastal communities' has been underway since October 2014. The project has been investigating six regional `hotspots': marine areas experiencing rapid warming. These are south-east Australia, Brazil, India, Solomon Islands, South Africa, and the Mozambique Channel and Madagascar. Rapid warming could be expected to have social, cultural and economic impacts that could affect these countries in different ways and may already be doing so. GULLS has focused on contributing to assessing and reducing the vulnerability of coastal communities and other stakeholders dependent on marine resources and to facilitate adaptation to climate change and variability through an integrated and trans-disciplinary approach. It includes participants from Australia, Brazil, India, Madagascar, New Zealand, South Africa, the United Kingdom and the United States of America. The research programme has been divided into six inter-linked components: ocean models, biological and ecological sensitivity analyses, system models, social vulnerability, policy mapping, and communication and education. This presentation will provide a brief overview of each of these components and describe the benefits that have resulted from the collaborative and transdisciplinary approach of GULLS. Following the standard vulnerability elements of exposure, sensitivity and adaptive capacity, the vulnerabilities of coastal communities and other stakeholders dependent on marine resources in the five hotspots will be compared using a set of indicators derived and populated from results of the research programme. The implications of similarities and differences between the hotspots for adaptation planning and options will be described.
- Full Text:
- Date Issued: 2016
The impact of geographical origin of two strains of the herbivore, Eccritotarsus catarinensis, on several fitness traits in response to temperature
- Ismail, Mohannad, Brooks, Margot
- Authors: Ismail, Mohannad , Brooks, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66914 , vital:28999 , ISSN 0306-4565 , https://doi.org/10.1016/j.jtherbio.2016.07.008
- Description: Publisher version , Adaptation to temperature changes is vital to reduce adverse effects on individuals, and some may present phenotypic changes, which might be accompanied with physiological costs in fitness traits. The objective of this study was to determine whether the two strains of the herbivore Eccritotarsus catarinensis, a biological control agent against water hyacinth in South Africa, differ in their responses to temperature according to their geographical origin. We experimentally quantified the responses of the two strains, at three constant temperatures: 20 °C, 25 °C and 30 °C, using laboratory cultures that originated from Brazil and Peru, where climates differ. Reproductive output, egg hatching rate, sex ratio and longevity were recorded at each temperature. Fitness traits for both strains were significantly reduced at 30 °C compared with 25 °C and 20 °C in two successive generations. Nonetheless, Peruvian individuals continued their development at 30 °C, whereas Brazilian individuals that succeeded in emerging did not continue their development. In contrast, sex ratio was unaffected by temperature. The Peruvian strain of E. catarinensis presented different phenotypes depending on temperature and was more adapted to extreme high temperature than the Brazilian strain. The tropical origin of the population induces the insect to tolerate the extreme high temperature. We suggest that the Peruvian strain could be better suited for release to control water hyacinth in nature, particularly in regions where temperature is high.
- Full Text: false
- Date Issued: 2016
- Authors: Ismail, Mohannad , Brooks, Margot
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/66914 , vital:28999 , ISSN 0306-4565 , https://doi.org/10.1016/j.jtherbio.2016.07.008
- Description: Publisher version , Adaptation to temperature changes is vital to reduce adverse effects on individuals, and some may present phenotypic changes, which might be accompanied with physiological costs in fitness traits. The objective of this study was to determine whether the two strains of the herbivore Eccritotarsus catarinensis, a biological control agent against water hyacinth in South Africa, differ in their responses to temperature according to their geographical origin. We experimentally quantified the responses of the two strains, at three constant temperatures: 20 °C, 25 °C and 30 °C, using laboratory cultures that originated from Brazil and Peru, where climates differ. Reproductive output, egg hatching rate, sex ratio and longevity were recorded at each temperature. Fitness traits for both strains were significantly reduced at 30 °C compared with 25 °C and 20 °C in two successive generations. Nonetheless, Peruvian individuals continued their development at 30 °C, whereas Brazilian individuals that succeeded in emerging did not continue their development. In contrast, sex ratio was unaffected by temperature. The Peruvian strain of E. catarinensis presented different phenotypes depending on temperature and was more adapted to extreme high temperature than the Brazilian strain. The tropical origin of the population induces the insect to tolerate the extreme high temperature. We suggest that the Peruvian strain could be better suited for release to control water hyacinth in nature, particularly in regions where temperature is high.
- Full Text: false
- Date Issued: 2016
The importance of long-term post-release studies in classical biological control: Insect–plant monitoring and public awareness of water hyacinth management (Pontederia crassipes) in Dique Los Sauces, Argentina
- Faltlhauser, Ana C, Jiménez, Nadia L, Righetti, Tomas, Visintin, Andrés M, Torrens, Javier, Salinas, Nicolás A, Mc Kay, Fernando, Hill, Martin P, Cordo, Hugo A, Sosa, Alejandro J
- Authors: Faltlhauser, Ana C , Jiménez, Nadia L , Righetti, Tomas , Visintin, Andrés M , Torrens, Javier , Salinas, Nicolás A , Mc Kay, Fernando , Hill, Martin P , Cordo, Hugo A , Sosa, Alejandro J
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424828 , vital:72187 , xlink:href="https://doi.org/10.1111/eea.13355"
- Description: Several components of classical biological control (CBC) programmes are necessary to assess the success of the management strategy (e.g., post-release monitoring) and also help prevent reintroductions or resurgences of invasive species (e.g., public awareness). Water hyacinth, Pontederia (= Eichhornia) crassipes (Mart.) Solms (Pontederiaceae) is an aquatic plant naturally distributed in the north-eastern region of the Del Plata basin in Argentina. In the 1960s it was introduced into the Dique Los Sauces reservoir located outside of its native range in La Rioja Province, in western Argentina, where it became invasive. The natural enemy, Neochetina bruchi Hustache (Coleoptera: Curculionidae), was intentionally introduced in 1974 to control the weed. To assess the success of this CBC programme, a long-term post-release study was conducted. Between 1965 and 2023, we monitored plant coverage, estimated N. bruchi densities, and quantified the associated damage by reanalysing previously published data and incorporating new sampling. We also conducted an online survey to analyse public knowledge and perception about this programme. Water hyacinth coverage fluctuated from its first record in 1965 (maximum coverage 90%) until the control of germinated plants (coverage 0%) in 2018. The plant decline was accompanied by an increase in the weevil population. In our survey, out of 325 respondents only a small group of mostly middle-aged and elderly people knew that the restoration had been achieved through a management strategy and even fewer were aware of the biocontrol approach taken. Respondents who had a positive approach to biological control were more aware of the management plan than respondents who had neutral or negative opinions. Neochetina bruchi has played a key factor in the control of P. crassipes. The intrinsic dynamics of these populations, the dormant seed bank, and the lack of public awareness support the need for long post-release evaluations including outreach campaigns to make a sustainable successful management programme.
- Full Text:
- Date Issued: 2023
- Authors: Faltlhauser, Ana C , Jiménez, Nadia L , Righetti, Tomas , Visintin, Andrés M , Torrens, Javier , Salinas, Nicolás A , Mc Kay, Fernando , Hill, Martin P , Cordo, Hugo A , Sosa, Alejandro J
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424828 , vital:72187 , xlink:href="https://doi.org/10.1111/eea.13355"
- Description: Several components of classical biological control (CBC) programmes are necessary to assess the success of the management strategy (e.g., post-release monitoring) and also help prevent reintroductions or resurgences of invasive species (e.g., public awareness). Water hyacinth, Pontederia (= Eichhornia) crassipes (Mart.) Solms (Pontederiaceae) is an aquatic plant naturally distributed in the north-eastern region of the Del Plata basin in Argentina. In the 1960s it was introduced into the Dique Los Sauces reservoir located outside of its native range in La Rioja Province, in western Argentina, where it became invasive. The natural enemy, Neochetina bruchi Hustache (Coleoptera: Curculionidae), was intentionally introduced in 1974 to control the weed. To assess the success of this CBC programme, a long-term post-release study was conducted. Between 1965 and 2023, we monitored plant coverage, estimated N. bruchi densities, and quantified the associated damage by reanalysing previously published data and incorporating new sampling. We also conducted an online survey to analyse public knowledge and perception about this programme. Water hyacinth coverage fluctuated from its first record in 1965 (maximum coverage 90%) until the control of germinated plants (coverage 0%) in 2018. The plant decline was accompanied by an increase in the weevil population. In our survey, out of 325 respondents only a small group of mostly middle-aged and elderly people knew that the restoration had been achieved through a management strategy and even fewer were aware of the biocontrol approach taken. Respondents who had a positive approach to biological control were more aware of the management plan than respondents who had neutral or negative opinions. Neochetina bruchi has played a key factor in the control of P. crassipes. The intrinsic dynamics of these populations, the dormant seed bank, and the lack of public awareness support the need for long post-release evaluations including outreach campaigns to make a sustainable successful management programme.
- Full Text:
- Date Issued: 2023
The influence of photoperiod on the reproductive physiology of the greater red musk shrew: Crocidura flavescens
- Hoole, C, McKechnie, Andrew E, Parker, Daniel M, Bennett, Nigel C
- Authors: Hoole, C , McKechnie, Andrew E , Parker, Daniel M , Bennett, Nigel C
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70136 , vital:29624 , https://doi.org/10.1139/cjz-2015-0128
- Description: Photoperiodism involves the use of both absolute measures of day length and the direction in which day length is changing as a cue for regulating seasonal changes in physiology and behaviour so that birth and lactation coincide with optimal resource availability, increasing offspring survival. Induced ovulation and opportunistic breeding is often found in species that are predominantly solitary and territorial. In this study, the photoperiodic reproductive responses of male greater red musk shrews (Crocidura flavescens (I. Geoffroy Saint-Hilaire, 1827)) were investigated in the laboratory. The presence of spermatozoa regardless of the light cycle, suggest that although the shrews are photoresponsive, they may be capable of breeding throughout the year. Significantly greater testicular volume and eminiferous tubule diameter following exposure to a short day-light cycle suggests that these animals may have breeding peaks that correspond to short days. The presence of epidermal spines on the penis indicates that the shrew is likely also an induced ovulator. Flexible breeding patterns combined with induced ovulation affords this solitary species the greatest chance of reproductive success.
- Full Text: false
- Date Issued: 2016
- Authors: Hoole, C , McKechnie, Andrew E , Parker, Daniel M , Bennett, Nigel C
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70136 , vital:29624 , https://doi.org/10.1139/cjz-2015-0128
- Description: Photoperiodism involves the use of both absolute measures of day length and the direction in which day length is changing as a cue for regulating seasonal changes in physiology and behaviour so that birth and lactation coincide with optimal resource availability, increasing offspring survival. Induced ovulation and opportunistic breeding is often found in species that are predominantly solitary and territorial. In this study, the photoperiodic reproductive responses of male greater red musk shrews (Crocidura flavescens (I. Geoffroy Saint-Hilaire, 1827)) were investigated in the laboratory. The presence of spermatozoa regardless of the light cycle, suggest that although the shrews are photoresponsive, they may be capable of breeding throughout the year. Significantly greater testicular volume and eminiferous tubule diameter following exposure to a short day-light cycle suggests that these animals may have breeding peaks that correspond to short days. The presence of epidermal spines on the penis indicates that the shrew is likely also an induced ovulator. Flexible breeding patterns combined with induced ovulation affords this solitary species the greatest chance of reproductive success.
- Full Text: false
- Date Issued: 2016
The influence of photoperiod on the reproductive physiology of the greater red musk shrew: Crocidura flavescens
- Hoole, C, McKechnie, Andrew E, Parker, Daniel M, Bennett, Nigel C
- Authors: Hoole, C , McKechnie, Andrew E , Parker, Daniel M , Bennett, Nigel C
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70157 , vital:29626 , https://doi.org/10.1139/cjz-2015-0128
- Description: Photoperiodism involves the use of both absolute measures of day length and the direction in which day length is changing as a cue for regulating seasonal changes in physiology and behaviour so that birth and lactation coincide with optimal resource availability, increasing offspring survival. Induced ovulation and opportunistic breeding is often found in species that are predominantly solitary and territorial. In this study, the photoperiodic reproductive responses of male greater red musk shrews (Crocidura flavescens (I. Geoffroy Saint-Hilaire, 1827)) were investigated in the laboratory. The presence of spermatozoa regardless of the light cycle, suggest that although the shrews are photoresponsive, they may be capable of breeding throughout the year. Significantly greater testicular volume and eminiferous tubule diameter following exposure to a short day-light cycle suggests that these animals may have breeding peaks that correspond to short days. The presence of epidermal spines on the penis indicates that the shrew is likely also an induced ovulator. Flexible breeding patterns combined with induced ovulation affords this solitary species the greatest chance of reproductive success.
- Full Text:
- Date Issued: 2016
- Authors: Hoole, C , McKechnie, Andrew E , Parker, Daniel M , Bennett, Nigel C
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70157 , vital:29626 , https://doi.org/10.1139/cjz-2015-0128
- Description: Photoperiodism involves the use of both absolute measures of day length and the direction in which day length is changing as a cue for regulating seasonal changes in physiology and behaviour so that birth and lactation coincide with optimal resource availability, increasing offspring survival. Induced ovulation and opportunistic breeding is often found in species that are predominantly solitary and territorial. In this study, the photoperiodic reproductive responses of male greater red musk shrews (Crocidura flavescens (I. Geoffroy Saint-Hilaire, 1827)) were investigated in the laboratory. The presence of spermatozoa regardless of the light cycle, suggest that although the shrews are photoresponsive, they may be capable of breeding throughout the year. Significantly greater testicular volume and eminiferous tubule diameter following exposure to a short day-light cycle suggests that these animals may have breeding peaks that correspond to short days. The presence of epidermal spines on the penis indicates that the shrew is likely also an induced ovulator. Flexible breeding patterns combined with induced ovulation affords this solitary species the greatest chance of reproductive success.
- Full Text:
- Date Issued: 2016