Seasonal metabolic adjustments in an avian evolutionary relict restricted to mountain habitat
- Oswald, Krista N, Lee, Alan T K, Smit, Ben
- Authors: Oswald, Krista N , Lee, Alan T K , Smit, Ben
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441638 , vital:73903 , https://doi.org/10.1016/j.jtherbio.2020.102815
- Description: For endotherms, maintaining body temperature during cold winters is energetically costly.Greater increase in winter maximum thermogenic capacity (Msum) has typically been correlated with improved cold tolerance. However, seasonal studies have shown equivocal direction change in basal metabolic rate (BMR) in winter, perhaps explained by latitude or phylogeny. We examined seasonal metabolic responses in the Cape rockjumper (Chaetops frenatus; “rockjumper”), a range-restricted mountain bird. We hypothesized that, given their mountain habitat preference, rockjumpers would be physiologically specialized for cooler air temperatures compared to other subtropical passerines. We measured body condition (using the ratio of Mb/tarsus), BMR, and Msum, in wild-living rockjumpers during winter and summer (n = 12 adults in winter –– 4 females, 8 males; n = 12 adults in summer –– 6 females, 6 males). We found birds had lesser BMR and thermal conductance, and greater Msum and body condition, in winter compared to summer. .
- Full Text:
- Authors: Oswald, Krista N , Lee, Alan T K , Smit, Ben
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441638 , vital:73903 , https://doi.org/10.1016/j.jtherbio.2020.102815
- Description: For endotherms, maintaining body temperature during cold winters is energetically costly.Greater increase in winter maximum thermogenic capacity (Msum) has typically been correlated with improved cold tolerance. However, seasonal studies have shown equivocal direction change in basal metabolic rate (BMR) in winter, perhaps explained by latitude or phylogeny. We examined seasonal metabolic responses in the Cape rockjumper (Chaetops frenatus; “rockjumper”), a range-restricted mountain bird. We hypothesized that, given their mountain habitat preference, rockjumpers would be physiologically specialized for cooler air temperatures compared to other subtropical passerines. We measured body condition (using the ratio of Mb/tarsus), BMR, and Msum, in wild-living rockjumpers during winter and summer (n = 12 adults in winter –– 4 females, 8 males; n = 12 adults in summer –– 6 females, 6 males). We found birds had lesser BMR and thermal conductance, and greater Msum and body condition, in winter compared to summer. .
- Full Text:
Segmentation of Tuta Absoluta’s Damage on Tomato Plants: A Computer Vision Approach
- Loyani, Loyani K, Bradshaw, Karen L, Machuze, Dina
- Authors: Loyani, Loyani K , Bradshaw, Karen L , Machuze, Dina
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440313 , vital:73765 , xlink:href="https://doi.org/10.1080/08839514.2021.1972254"
- Description: Tuta absoluta is a major threat to tomato production, causing losses ranging from 80% to 100% when not properly managed. Early detection of T. absoluta’s effects on tomato plants is important in controlling and preventing severe pest damage on tomatoes. In this study, we propose semantic and instance segmentation models based on U-Net and Mask RCNN, deep Convolutional Neural Networks (CNN) to segment the effects of T. absoluta on tomato leaf images at pixel level using field data. The results show that Mask RCNN achieved a mean Average Precision of 85.67%, while the U-Net model achieved an Intersection over Union of 78.60% and Dice coefficient of 82.86%. Both models can precisely generate segmentations indicating the exact spots/areas infested by T. absoluta in tomato leaves. The model will help farmers and extension officers make informed decisions to improve tomato productivity and rescue farmers from annual losses.
- Full Text:
- Authors: Loyani, Loyani K , Bradshaw, Karen L , Machuze, Dina
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440313 , vital:73765 , xlink:href="https://doi.org/10.1080/08839514.2021.1972254"
- Description: Tuta absoluta is a major threat to tomato production, causing losses ranging from 80% to 100% when not properly managed. Early detection of T. absoluta’s effects on tomato plants is important in controlling and preventing severe pest damage on tomatoes. In this study, we propose semantic and instance segmentation models based on U-Net and Mask RCNN, deep Convolutional Neural Networks (CNN) to segment the effects of T. absoluta on tomato leaf images at pixel level using field data. The results show that Mask RCNN achieved a mean Average Precision of 85.67%, while the U-Net model achieved an Intersection over Union of 78.60% and Dice coefficient of 82.86%. Both models can precisely generate segmentations indicating the exact spots/areas infested by T. absoluta in tomato leaves. The model will help farmers and extension officers make informed decisions to improve tomato productivity and rescue farmers from annual losses.
- Full Text:
Sex, gender and Uvalo/Letswalo centred spirituality
- Magadla, Siphokazi, Magoqwana, Babalwa, Motsemme, Nthabiseng, Mohoto, Lieketso
- Authors: Magadla, Siphokazi , Magoqwana, Babalwa , Motsemme, Nthabiseng , Mohoto, Lieketso
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298663 , vital:57725 , xlink:href="https://doi.org/10.1080/02589001.2021.1909711"
- Description: In Male Daughters, Female Husbands (1987) Amadiume argues that the female orientation of Nnobi society and its emphasis on female industriousness is ‘derived from goddess Idemili – the ancestral religious deity’ (27). While Christianity dominates the outlook and conservatism of the post-colonial African state, we are seeing a growing public presence of African spiritual practitioners in southern Africa. The interview with Lieketso Gogo Mapitsi Mohoto reflects on her journey of becoming a healer. She uses the concept of ‘uvalo' to argue for deeper connected spiritual awareness within this practice of healing. Using the Nguni concept of uvalo, she refers to the fluid meaning of intuition also known as Umbilini among Xhosa-speaking people, while Sesotho speakers call it Letswalo. This intimate connection with the Divine can sometimes mean a sense of fear for ordinary people, while it promotes a deep sense of knowing for the spiritually conscious. Gogo Mapitsi's connections between spirituality and land, speak to Amadiume’s matrifocal understanding of productivity as linked to the goddess Idemili in Nnobi histories. Gogo Mapitsi reminds us that the multiple health, economic, psychological crises we face today are linked 'to how uvalo works.' She tells us that the 'cultivation of that inner knowing and the cultivation of trust in that knowing' is central to how a Sangoma understands and responds to the needs of their society.
- Full Text:
- Authors: Magadla, Siphokazi , Magoqwana, Babalwa , Motsemme, Nthabiseng , Mohoto, Lieketso
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298663 , vital:57725 , xlink:href="https://doi.org/10.1080/02589001.2021.1909711"
- Description: In Male Daughters, Female Husbands (1987) Amadiume argues that the female orientation of Nnobi society and its emphasis on female industriousness is ‘derived from goddess Idemili – the ancestral religious deity’ (27). While Christianity dominates the outlook and conservatism of the post-colonial African state, we are seeing a growing public presence of African spiritual practitioners in southern Africa. The interview with Lieketso Gogo Mapitsi Mohoto reflects on her journey of becoming a healer. She uses the concept of ‘uvalo' to argue for deeper connected spiritual awareness within this practice of healing. Using the Nguni concept of uvalo, she refers to the fluid meaning of intuition also known as Umbilini among Xhosa-speaking people, while Sesotho speakers call it Letswalo. This intimate connection with the Divine can sometimes mean a sense of fear for ordinary people, while it promotes a deep sense of knowing for the spiritually conscious. Gogo Mapitsi's connections between spirituality and land, speak to Amadiume’s matrifocal understanding of productivity as linked to the goddess Idemili in Nnobi histories. Gogo Mapitsi reminds us that the multiple health, economic, psychological crises we face today are linked 'to how uvalo works.' She tells us that the 'cultivation of that inner knowing and the cultivation of trust in that knowing' is central to how a Sangoma understands and responds to the needs of their society.
- Full Text:
Skill and Earnings Amongst Golfers on the Southern‐African Sunshine Tour
- Botha, Ferdi, Fraser, Gavin C G, Rhoads, Thomas A
- Authors: Botha, Ferdi , Fraser, Gavin C G , Rhoads, Thomas A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/473021 , vital:77599 , https://doi.org/10.1111/saje.12269
- Description: This paper estimates the determinants of the success of golfers on the Southern‐African Sunshine Tour. Using a simultaneous‐quantile regression approach and real earnings per tournament as a measure of success, a higher greens‐in‐regulation percentage and a lower number of putts per greens‐in‐regulation are associated with higher earnings. Calculations of the value of the marginal product of key golfer skills suggest a dynamic human capital acquisition process for many Sunshine Tour golfers at the earliest stages of their professional golf career.
- Full Text:
- Authors: Botha, Ferdi , Fraser, Gavin C G , Rhoads, Thomas A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/473021 , vital:77599 , https://doi.org/10.1111/saje.12269
- Description: This paper estimates the determinants of the success of golfers on the Southern‐African Sunshine Tour. Using a simultaneous‐quantile regression approach and real earnings per tournament as a measure of success, a higher greens‐in‐regulation percentage and a lower number of putts per greens‐in‐regulation are associated with higher earnings. Calculations of the value of the marginal product of key golfer skills suggest a dynamic human capital acquisition process for many Sunshine Tour golfers at the earliest stages of their professional golf career.
- Full Text:
Snapshot Safari: A large-scale collaborative to monitor Africa's remarkable biodiversity
- Pardo, Lain E, Bombaci, Sara, Huebner, Sarah E, Somers, Michael J, Fritz, Herve, Downs, Colleen, Guthmann, Abby, Hetem, Robyn S, Keith, Mark, le Roux, Aliza, Mgqatsa, Nokubonga, Packer, Craig, Palmer, Meredith S, Parker, Daniel M, Peel, Mike, Slotow, Rob, Strauss, W. Maartin, Swanepoel, Lourens, Tambling, Craig J, Tsie, Nairobi, Vermeulen, Mika, Willi, Marco, Jachowski, David S, Venter, Jan A
- Authors: Pardo, Lain E , Bombaci, Sara , Huebner, Sarah E , Somers, Michael J , Fritz, Herve , Downs, Colleen , Guthmann, Abby , Hetem, Robyn S , Keith, Mark , le Roux, Aliza , Mgqatsa, Nokubonga , Packer, Craig , Palmer, Meredith S , Parker, Daniel M , Peel, Mike , Slotow, Rob , Strauss, W. Maartin , Swanepoel, Lourens , Tambling, Craig J , Tsie, Nairobi , Vermeulen, Mika , Willi, Marco , Jachowski, David S , Venter, Jan A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462669 , vital:76324 , xlink:href="http://dx.doi.org/10.17159/sajs.2021/8134"
- Description: Nature is experiencing degradation and extinction rates never recorded before in the history of Earth. Consequently, continuous large-scale monitoring programmes are critical, not only to provide insights into population trends but also to aid in understanding factors associated with altering population dynamics at various temporal and spatial scales. Continuous monitoring is important not only for tracking rare or threatened species but also to detect the increase of potentially invasive species4, and the trends in the populations of common species, which in some regions are declining even more rapidly than are rare species. The combination of citizen science and cutting-edge technologies has improved monitoring programmes. In this regard, camera traps have become a popular tool to engage with society while obtaining accurate scientific data. The importance of advances in technological monitoring has even been highlighted by the United Nations Environment Programme (UNEP) through the proposed 'Digital Ecosystem framework', a complex distributed network or interconnected socio-technological system.
- Full Text:
- Authors: Pardo, Lain E , Bombaci, Sara , Huebner, Sarah E , Somers, Michael J , Fritz, Herve , Downs, Colleen , Guthmann, Abby , Hetem, Robyn S , Keith, Mark , le Roux, Aliza , Mgqatsa, Nokubonga , Packer, Craig , Palmer, Meredith S , Parker, Daniel M , Peel, Mike , Slotow, Rob , Strauss, W. Maartin , Swanepoel, Lourens , Tambling, Craig J , Tsie, Nairobi , Vermeulen, Mika , Willi, Marco , Jachowski, David S , Venter, Jan A
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/462669 , vital:76324 , xlink:href="http://dx.doi.org/10.17159/sajs.2021/8134"
- Description: Nature is experiencing degradation and extinction rates never recorded before in the history of Earth. Consequently, continuous large-scale monitoring programmes are critical, not only to provide insights into population trends but also to aid in understanding factors associated with altering population dynamics at various temporal and spatial scales. Continuous monitoring is important not only for tracking rare or threatened species but also to detect the increase of potentially invasive species4, and the trends in the populations of common species, which in some regions are declining even more rapidly than are rare species. The combination of citizen science and cutting-edge technologies has improved monitoring programmes. In this regard, camera traps have become a popular tool to engage with society while obtaining accurate scientific data. The importance of advances in technological monitoring has even been highlighted by the United Nations Environment Programme (UNEP) through the proposed 'Digital Ecosystem framework', a complex distributed network or interconnected socio-technological system.
- Full Text:
Social Cohesion Through Sonic Intervention
- Authors: McConnachie, Boudina E
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/480257 , vital:78411 , ISBN 9781800795846
- Description: Abstract that must end in a full stop.
- Full Text:
- Authors: McConnachie, Boudina E
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/480257 , vital:78411 , ISBN 9781800795846
- Description: Abstract that must end in a full stop.
- Full Text:
Solar Driven Photocatalytic Activity of Porphyrin Sensitized TiO2
- Otieno, Sebastien, Lanterna, Anabel E, Mack, John, Derese, Solomon, Amuhaya, Edith K, Nyokong, Tebello, Scaiano, Juan C
- Authors: Otieno, Sebastien , Lanterna, Anabel E , Mack, John , Derese, Solomon , Amuhaya, Edith K , Nyokong, Tebello , Scaiano, Juan C
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190612 , vital:45010 , xlink:href="https://doi.org/10.3390/molecules26113131"
- Description: The absence of a secure long-term sustainable energy supply is recognized as a major worldwide technological challenge. The generation of H2 through photocatalysis is an environmentally friendly alternative that can help solve the energy problem. Thus, the development of semiconductor materials that can absorb solar light is an attractive approach. TiO2 has a wide bandgap that suffers from no activity in the visible spectrum, limiting its use of solar radiation. In this research, the semiconductor absorption profile was extended into the visible region of the solar spectrum by preparing porphyrin-TiO2 (P-TiO2 ) composites of meso-tetra(4-bromophenyl)porphyrin (PP1) and meso-tetra(5-bromo-2-thienyl)porphyrin (PP2) and their In(III), Zn(II) and Ga(III) metal complexes. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were performed on the porphyrins to gain insight into their electron injection capability. The results demonstrate that P-TiO2 systems merit further in-depth study for applications that require efficient photocatalytic H2 generation.
- Full Text:
- Authors: Otieno, Sebastien , Lanterna, Anabel E , Mack, John , Derese, Solomon , Amuhaya, Edith K , Nyokong, Tebello , Scaiano, Juan C
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190612 , vital:45010 , xlink:href="https://doi.org/10.3390/molecules26113131"
- Description: The absence of a secure long-term sustainable energy supply is recognized as a major worldwide technological challenge. The generation of H2 through photocatalysis is an environmentally friendly alternative that can help solve the energy problem. Thus, the development of semiconductor materials that can absorb solar light is an attractive approach. TiO2 has a wide bandgap that suffers from no activity in the visible spectrum, limiting its use of solar radiation. In this research, the semiconductor absorption profile was extended into the visible region of the solar spectrum by preparing porphyrin-TiO2 (P-TiO2 ) composites of meso-tetra(4-bromophenyl)porphyrin (PP1) and meso-tetra(5-bromo-2-thienyl)porphyrin (PP2) and their In(III), Zn(II) and Ga(III) metal complexes. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were performed on the porphyrins to gain insight into their electron injection capability. The results demonstrate that P-TiO2 systems merit further in-depth study for applications that require efficient photocatalytic H2 generation.
- Full Text:
Specialty Grand Challenges in Urban Agriculture: Ecological and Social Approaches to Sustainability Transformations
- Zimmerer, Karl S, Bell, Martha G, Chirisa, Innocent, Duvall, Chris S, Egerer, Monika, Hung, Po-Yi, Lerner, Amy M, Shackleton, Charlie M, Ward, James David, Yacamán Ochoa, Carolina
- Authors: Zimmerer, Karl S , Bell, Martha G , Chirisa, Innocent , Duvall, Chris S , Egerer, Monika , Hung, Po-Yi , Lerner, Amy M , Shackleton, Charlie M , Ward, James David , Yacamán Ochoa, Carolina
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175779 , vital:42623 , https://doi.org/10.3389/fsufs.2021.668561
- Description: This synopsis of the Grand Challenges of Urban Agriculture (UA) is framed by the urgent need to understand and strengthen the expanding yet highly diverse roles of UA amid rapid global urbanization, failures of predominant food systems, and crises in systems of physical and mental health. More than half of humanity lives in cities today and by 2030 this is projected to grow to 60.4 percent, ~5 billion people (UN Habitat, 2020). More than 90 percent of urban demographic increase is anticipated to take place in the developing world.
- Full Text:
- Authors: Zimmerer, Karl S , Bell, Martha G , Chirisa, Innocent , Duvall, Chris S , Egerer, Monika , Hung, Po-Yi , Lerner, Amy M , Shackleton, Charlie M , Ward, James David , Yacamán Ochoa, Carolina
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175779 , vital:42623 , https://doi.org/10.3389/fsufs.2021.668561
- Description: This synopsis of the Grand Challenges of Urban Agriculture (UA) is framed by the urgent need to understand and strengthen the expanding yet highly diverse roles of UA amid rapid global urbanization, failures of predominant food systems, and crises in systems of physical and mental health. More than half of humanity lives in cities today and by 2030 this is projected to grow to 60.4 percent, ~5 billion people (UN Habitat, 2020). More than 90 percent of urban demographic increase is anticipated to take place in the developing world.
- Full Text:
Spectral Resistance in Andile Khumalo's Bells Die Out
- Authors: Fourie, William
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/484438 , vital:78906 , xlink:href="10.1353/pnm.2021.0013"
- Description: “It was remarked wittily . . . that the black South African award-winner in the “Serious” Music genre had written Central European intellectual music, while one of the white South African award-winners in the Jazz/Popular Music genre had written Zimbabwean folk-music!”—Mzilikazi Khumalo. Perhaps a witticism but certainly a damning statement on the racialized cultural legacy of the apartheid regime, this remark was made in 2002 when composer Andile Khumalo won a number of awards at the Southern African Music Rights Organization’s Overseas Scholarship Competition. The irony offered by the commentator’s locution has to do with the reversal of expectations: a decade after the end of the apartheid regime, under which such an occurrence would have been impossible, it is still striking that a black composer could win prizes for writing Western art music. During the preceding half-century, after all, this music was seen as the “bounteous heritage of the white people,” and artificial racial-cultural demarcations attempted to prohibit composing across the “racial line.” African music was for Africans, the cultural ideology of separate development decreed, and European music was for whites.
- Full Text:
- Authors: Fourie, William
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/484438 , vital:78906 , xlink:href="10.1353/pnm.2021.0013"
- Description: “It was remarked wittily . . . that the black South African award-winner in the “Serious” Music genre had written Central European intellectual music, while one of the white South African award-winners in the Jazz/Popular Music genre had written Zimbabwean folk-music!”—Mzilikazi Khumalo. Perhaps a witticism but certainly a damning statement on the racialized cultural legacy of the apartheid regime, this remark was made in 2002 when composer Andile Khumalo won a number of awards at the Southern African Music Rights Organization’s Overseas Scholarship Competition. The irony offered by the commentator’s locution has to do with the reversal of expectations: a decade after the end of the apartheid regime, under which such an occurrence would have been impossible, it is still striking that a black composer could win prizes for writing Western art music. During the preceding half-century, after all, this music was seen as the “bounteous heritage of the white people,” and artificial racial-cultural demarcations attempted to prohibit composing across the “racial line.” African music was for Africans, the cultural ideology of separate development decreed, and European music was for whites.
- Full Text:
Strengthening Environment and Sustainability Subject Knowledge Curriculum Challenges and Opportunities
- Schudel, Ingrid J, Lotz-Sisitka, Heila
- Authors: Schudel, Ingrid J , Lotz-Sisitka, Heila
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435045 , vital:73126 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: This chapter serves as a positioning paper for the chapters that follow in which different environment and sustainability knowledge foci will be explored in the South African Curriculum Assessment Policy Statements (CAPS). As a series of interconnected and cross-cutting complexities, environment and sustainability content knowledge has relevance for, and is widely distributed across, different phases and subjects in the school curriculum (see discussion of environmental content knowledge in Schudel and Lotz-Sisitka, Chapter 1; Lotz-Sisitka et al., Chapter 6; Msezane, Chapter 7). Knowledge that makes its way into education curricula and teaching is produced within the wider scientific context. Bernstein (2000), in his theory of the pedagogical device, refers to this as the ‘Field of Production’. A significant knowledge-producing community for sustainability concerns is the global change research community (international and national)(South Africa DST 2010). Examining their research outputs and discourses can provide important insights for the development of knowledge in what Bernstein names ‘regions’, where singular disciplines such as Science (eg climate sciences/biodiversity sciences/water sciences/health sciences), come together with other singular disciplines such as education. Bernstein suggests that a first level of knowledge recontextualisation in the Field of Production occurs in these regions (eg where environmental educators or science educators recontextualise the knowledge of scientists).
- Full Text:
- Authors: Schudel, Ingrid J , Lotz-Sisitka, Heila
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435045 , vital:73126 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: This chapter serves as a positioning paper for the chapters that follow in which different environment and sustainability knowledge foci will be explored in the South African Curriculum Assessment Policy Statements (CAPS). As a series of interconnected and cross-cutting complexities, environment and sustainability content knowledge has relevance for, and is widely distributed across, different phases and subjects in the school curriculum (see discussion of environmental content knowledge in Schudel and Lotz-Sisitka, Chapter 1; Lotz-Sisitka et al., Chapter 6; Msezane, Chapter 7). Knowledge that makes its way into education curricula and teaching is produced within the wider scientific context. Bernstein (2000), in his theory of the pedagogical device, refers to this as the ‘Field of Production’. A significant knowledge-producing community for sustainability concerns is the global change research community (international and national)(South Africa DST 2010). Examining their research outputs and discourses can provide important insights for the development of knowledge in what Bernstein names ‘regions’, where singular disciplines such as Science (eg climate sciences/biodiversity sciences/water sciences/health sciences), come together with other singular disciplines such as education. Bernstein suggests that a first level of knowledge recontextualisation in the Field of Production occurs in these regions (eg where environmental educators or science educators recontextualise the knowledge of scientists).
- Full Text:
Supporting Student Teachers to Teach Catchment and River Management in Geography
- Authors: Heath, Gavin , O’Donoghue, R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435167 , vital:73135 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The inclusion of new environmental knowledge in the South African Geography Curriculum and Assessment Policy Statement (CAPS) has meant that many student teachers are unprepared to teach a systemic process like catchment and river management, which concerns the management of water catchment basins and the rivers within. New environ-mental knowledge, by definition, involves systems thinking towards a grasp of social-ecological systems, notably cause and effect processes, and circularity within a system. A so-cial-ecological system is the complex relationship between the social and ecological processes on a parcel of land. The need for such systems thinking is implicit in the catchment and river management component of the CAPS (South Africa DBE 2011). The teaching of a case study of a catchment management system (which is the management system that governs a water catchment basin) has never been included in any previous curriculum. Water management has devel-oped on a widening scale into the 21st century in South Afri-ca, but there was little comprehensive data on catchment management systems until 2017. It was only in July 2017 that a draft catchment management strategy was published. Hence it is not surprising that no curriculum case studies ex-ist since there was no data to base them on (Meissner et al. 2017). An internet search in June 2020 uncovered no trace of any catchment management strategy for the more densely populated and, arguably, more significant eastern catch-ments of the country.
- Full Text:
- Authors: Heath, Gavin , O’Donoghue, R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435167 , vital:73135 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The inclusion of new environmental knowledge in the South African Geography Curriculum and Assessment Policy Statement (CAPS) has meant that many student teachers are unprepared to teach a systemic process like catchment and river management, which concerns the management of water catchment basins and the rivers within. New environ-mental knowledge, by definition, involves systems thinking towards a grasp of social-ecological systems, notably cause and effect processes, and circularity within a system. A so-cial-ecological system is the complex relationship between the social and ecological processes on a parcel of land. The need for such systems thinking is implicit in the catchment and river management component of the CAPS (South Africa DBE 2011). The teaching of a case study of a catchment management system (which is the management system that governs a water catchment basin) has never been included in any previous curriculum. Water management has devel-oped on a widening scale into the 21st century in South Afri-ca, but there was little comprehensive data on catchment management systems until 2017. It was only in July 2017 that a draft catchment management strategy was published. Hence it is not surprising that no curriculum case studies ex-ist since there was no data to base them on (Meissner et al. 2017). An internet search in June 2020 uncovered no trace of any catchment management strategy for the more densely populated and, arguably, more significant eastern catch-ments of the country.
- Full Text:
Synthesis and emerging frontiers in social-ecological systems research methods
- Schluter, Maja, Biggs, Reinette, Clements, Hayley, de Vos, Alta, Maciejewski, Kristine, Preiser, Rika
- Authors: Schluter, Maja , Biggs, Reinette , Clements, Hayley , de Vos, Alta , Maciejewski, Kristine , Preiser, Rika
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433887 , vital:73007 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Social-ecological systems (SES) research is a rapidly emerging new research domain within the broader emerging area of sustainability science. It is largely a problem-driven and action-oriented field, motivated by the immense sustainability and equity-related challenges facing society (see Chapter 1). Social-ecological systems research is based on an understanding that SES are complex adaptive systems (CAS), where social and ecological dynamics are deeply intertwined, and give rise to features and problems that cannot be understood or addressed by studying these dimensions in isolation (see Chapter 2). The field draws on and combines methods from both natural and social sciences, and combines quantitative and qualitative approaches. As such, SES research is characterised by epistemological and methodological pluralism, which is challenging for those entering the field and has complex implications for the research process, methods and ethical considerations to be taken into account in SES research (see Chapter 3). This book aims to clarify and synthesise this plurality by providing an introduction to SES research (Part 1), and the diversity of methods currently used in the field (Part 2). The aim of this final chapter (Part 3) is to provide a synthesis of the current landscape of SES methods, critically reflect on the methods with respect to their ability to address systemic features of SES and discuss some of the most common methodological challenges associated with the complex adaptive and intertwined nature of SES. Based on this synthesis, we identify methodological gaps and discuss novel methods and method combinations that may help to address these gaps and move the field forward.
- Full Text:
- Authors: Schluter, Maja , Biggs, Reinette , Clements, Hayley , de Vos, Alta , Maciejewski, Kristine , Preiser, Rika
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433887 , vital:73007 , ISBN 9781000401516 , https://library.oapen.org/handle/20.500.12657/49560
- Description: Social-ecological systems (SES) research is a rapidly emerging new research domain within the broader emerging area of sustainability science. It is largely a problem-driven and action-oriented field, motivated by the immense sustainability and equity-related challenges facing society (see Chapter 1). Social-ecological systems research is based on an understanding that SES are complex adaptive systems (CAS), where social and ecological dynamics are deeply intertwined, and give rise to features and problems that cannot be understood or addressed by studying these dimensions in isolation (see Chapter 2). The field draws on and combines methods from both natural and social sciences, and combines quantitative and qualitative approaches. As such, SES research is characterised by epistemological and methodological pluralism, which is challenging for those entering the field and has complex implications for the research process, methods and ethical considerations to be taken into account in SES research (see Chapter 3). This book aims to clarify and synthesise this plurality by providing an introduction to SES research (Part 1), and the diversity of methods currently used in the field (Part 2). The aim of this final chapter (Part 3) is to provide a synthesis of the current landscape of SES methods, critically reflect on the methods with respect to their ability to address systemic features of SES and discuss some of the most common methodological challenges associated with the complex adaptive and intertwined nature of SES. Based on this synthesis, we identify methodological gaps and discuss novel methods and method combinations that may help to address these gaps and move the field forward.
- Full Text:
Synthesis and trypanocidal activity of substituted 2, 4-diarylquinoline derivatives
- Oluwafemi, Kola A, Phunguphungu, Siyolise, Gqunu, Sinalo, Isaacs, Michelle, Hoppe, Heinrich C, Klein, Rosalyn, Kaye, Perry T
- Authors: Oluwafemi, Kola A , Phunguphungu, Siyolise , Gqunu, Sinalo , Isaacs, Michelle , Hoppe, Heinrich C , Klein, Rosalyn , Kaye, Perry T
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/477683 , vital:78111 , xlink:href="https://doi.org/10.24820/ark.5550190.p011.499"
- Description: A small library of nine, novel 2, 4-diarylquinoline derivatives has been prepared in high yield via convenient one-or two-step routes from a series of substituted 2-aminobenzophenones. None of the products exhibited toxicity at 20 μM against human cervix adenocarcinoma (HeLa) cells, while many of them exhibited encouraging trypanocidal activity against T. brucei brucei (a parasite responsible for African cattle trypanosomiasis)-some with IC50 values in the range 2.8–6.2 μM.
- Full Text:
- Authors: Oluwafemi, Kola A , Phunguphungu, Siyolise , Gqunu, Sinalo , Isaacs, Michelle , Hoppe, Heinrich C , Klein, Rosalyn , Kaye, Perry T
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/477683 , vital:78111 , xlink:href="https://doi.org/10.24820/ark.5550190.p011.499"
- Description: A small library of nine, novel 2, 4-diarylquinoline derivatives has been prepared in high yield via convenient one-or two-step routes from a series of substituted 2-aminobenzophenones. None of the products exhibited toxicity at 20 μM against human cervix adenocarcinoma (HeLa) cells, while many of them exhibited encouraging trypanocidal activity against T. brucei brucei (a parasite responsible for African cattle trypanosomiasis)-some with IC50 values in the range 2.8–6.2 μM.
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Synthesis of a near infrared-actuated phthalocyanine-lipid vesicle system for augmented photodynamic therapy
- Nwahara, Namdi, Managa, Muthumuni, Stoffels, Mihlali, Britton, Jonathan, Prinsloo, Earl, Nyokong, Tebello
- Authors: Nwahara, Namdi , Managa, Muthumuni , Stoffels, Mihlali , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185395 , vital:44383 , xlink:href="https://doi.org/10.1016/j.synthmet.2021.116811"
- Description: The efficacy of photodynamic therapy (PDT) is often limited by the poor bio-distributive properties of conventional photosensitizers and the local hypoxic microenvironment that characterises most solid tumours. Herein, a novel in situ oxygenic lipid formulation for photodynamic therapy (PDT) is reported. Such a hybrid was synthesized by adsorbing bimetallic nanozyme, MnO2@PtNPs (NPs = nanoparticles) onto graphene quantum dots (GQDs) – zinc (II) phthalocyanine conjugates, followed by liposomal encapsulation, affording it enhanced water solubility. The MnO2@PtNPs, which are is shown to possess excellent catalase-like properties surpassing that of MnO2 or PtNPs alone, serves to catalyze H2O2 to O2, while the zinc (II) phthalocyanine (1) serves to transform the formed oxygen to generate cytotoxic singlet oxygen immediately. We show that by combining each function of the respective building blocks, the as-synthesized 1-GQDs-MnO2@PtNPs-liposomes not only maintains the properties of oxygen supplementation through H2O2 catalysis but also displays cooperative properties for enhanced singlet oxygen production. Consequently, a remarkably improved PDT efficacy was observed for 1-GQDs-MnO2@PtNPs-liposomes in both normoxia and hypoxia. These results demonstrate the potential applicability of such nanozyme constituted 1-GQDs-MnO2@PtNPs-liposomes for achieving tumour treatment in hypoxic conditions by PDT.
- Full Text:
- Authors: Nwahara, Namdi , Managa, Muthumuni , Stoffels, Mihlali , Britton, Jonathan , Prinsloo, Earl , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/185395 , vital:44383 , xlink:href="https://doi.org/10.1016/j.synthmet.2021.116811"
- Description: The efficacy of photodynamic therapy (PDT) is often limited by the poor bio-distributive properties of conventional photosensitizers and the local hypoxic microenvironment that characterises most solid tumours. Herein, a novel in situ oxygenic lipid formulation for photodynamic therapy (PDT) is reported. Such a hybrid was synthesized by adsorbing bimetallic nanozyme, MnO2@PtNPs (NPs = nanoparticles) onto graphene quantum dots (GQDs) – zinc (II) phthalocyanine conjugates, followed by liposomal encapsulation, affording it enhanced water solubility. The MnO2@PtNPs, which are is shown to possess excellent catalase-like properties surpassing that of MnO2 or PtNPs alone, serves to catalyze H2O2 to O2, while the zinc (II) phthalocyanine (1) serves to transform the formed oxygen to generate cytotoxic singlet oxygen immediately. We show that by combining each function of the respective building blocks, the as-synthesized 1-GQDs-MnO2@PtNPs-liposomes not only maintains the properties of oxygen supplementation through H2O2 catalysis but also displays cooperative properties for enhanced singlet oxygen production. Consequently, a remarkably improved PDT efficacy was observed for 1-GQDs-MnO2@PtNPs-liposomes in both normoxia and hypoxia. These results demonstrate the potential applicability of such nanozyme constituted 1-GQDs-MnO2@PtNPs-liposomes for achieving tumour treatment in hypoxic conditions by PDT.
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Synthesis, characterization, computational studies and DPPH scavenging activity of some triazatetracyclic derivatives
- Odame, Felix, Hosten, Eric C, Betz, Richard, Krause, Jason, Frost, Carminita L, Lobb, Kevin A, Tshentu, Zenixole R
- Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Krause, Jason , Frost, Carminita L , Lobb, Kevin A , Tshentu, Zenixole R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451186 , vital:75026 , xlink:href="https://doi.org/10.1007/s13738-021-02158-3"
- Description: Some dihydrobenzo[4,5]imidazo[1,2-c]quinazolines have been synthesized from aldehydes and ketones, using the ketones as both reagents and solvents and tetrahydrofuran (THF) as the solvent for the aldehydes, to yield the triazatetracyclics. The compounds have been characterized with spectroscopy and microanalysis. The crystal structures of 9,9-dimethyl-8,10,17- triazatetracyclo[8.7.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaene (I), 9-butyl-9-methyl-8,10,17-triazatetracyclo[8.7.0.02 , 7 .011,16]heptadeca-(17),2,4,6,11(16),12,14-heptaene (III) and 9-phenyl-8,10,17-triazatetracyclo[8.7.0 02 7.011,16] heptadeca-1(17),2,4,6,11(16),12,14-heptaene (VIII) have been discussed. The computed NMR, IR, molecular electrostatic potential and frontier molecular orbitals of compounds I, III and VIII have been discussed. The M06 functional gave most of its values closest to the experimental values for the bond lengths and bond angles of compounds I and III. For compound VIII, none of the functionals gave values for bond lengths and bond angles that were consistent with the experimental values, but M06 gave values closest to experimental values. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of the triazatetracyclics showed that compound I exhibits signifcant DPPH scavenging activity with an IC50 of 56.18 µM compared to 2.37 µM for ascorbic acid.
- Full Text:
- Authors: Odame, Felix , Hosten, Eric C , Betz, Richard , Krause, Jason , Frost, Carminita L , Lobb, Kevin A , Tshentu, Zenixole R
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451186 , vital:75026 , xlink:href="https://doi.org/10.1007/s13738-021-02158-3"
- Description: Some dihydrobenzo[4,5]imidazo[1,2-c]quinazolines have been synthesized from aldehydes and ketones, using the ketones as both reagents and solvents and tetrahydrofuran (THF) as the solvent for the aldehydes, to yield the triazatetracyclics. The compounds have been characterized with spectroscopy and microanalysis. The crystal structures of 9,9-dimethyl-8,10,17- triazatetracyclo[8.7.02,7.011,16]heptadeca-1(17),2,4,6,11(16),12,14-heptaene (I), 9-butyl-9-methyl-8,10,17-triazatetracyclo[8.7.0.02 , 7 .011,16]heptadeca-(17),2,4,6,11(16),12,14-heptaene (III) and 9-phenyl-8,10,17-triazatetracyclo[8.7.0 02 7.011,16] heptadeca-1(17),2,4,6,11(16),12,14-heptaene (VIII) have been discussed. The computed NMR, IR, molecular electrostatic potential and frontier molecular orbitals of compounds I, III and VIII have been discussed. The M06 functional gave most of its values closest to the experimental values for the bond lengths and bond angles of compounds I and III. For compound VIII, none of the functionals gave values for bond lengths and bond angles that were consistent with the experimental values, but M06 gave values closest to experimental values. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity of the triazatetracyclics showed that compound I exhibits signifcant DPPH scavenging activity with an IC50 of 56.18 µM compared to 2.37 µM for ascorbic acid.
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Synthesis, spectroscopic and nonlinear optical properties of asymmetric A3B type phthalocyanine complexes
- Authors: Mugeza, Rhulani Donney
- Date: 2021
- Subjects: Spectrum analysis , Mass spectrometry , Phthalocyanines
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171667 , vital:42108
- Description: This work reports on the synthesis of symmetrical and asymmetrical A 3 B type metal free, cobalt and zinc Phthalocyanines (Pc) .A wide range of spectroscopic techniques such as Uv - visible absorption (UV), magnetic circular dichroism (MCD), mass spectrometry, elemental analysis, IR spectroscopy and time correlated single photo n counting spectroscopy (TCSPC) have been used to study the spectroscopic properties of the phthalocyanine complexes. The Z - scan technique was used to comparatively investigate the nonlinear absorption coefficient ( 휷 ) and the nonlinear refraction index ( 풏 ퟐ ) of the synthesized complexes. The following trend was obtained for the synthesized Pc’s in terms of the 휷 values 7.25 × 10 − 10 ( 4b ) > 3.76 × 10 − 10 ( 4a ) > 3.52 × 10 − 10 ( 4c ) > 2.29 × 10 − 10 ( 3c ) > 1.68 × 10 − 10 ( 3a ) > 1.65 × 10 − 10 ( 3b ) mW - 1 . The 휷 values trend of synthesized Pc complexes show that the asymmetrical A 3 B type metal free, cobalt and zinc Pc complexes ( 4a , 4b and 4c ) have larger 휷 values as compared to the octa - substituted symmetrical metal free, cobalt and zinc Pc complexes ( 3a , 3b and 3c ) which is attributed to the low symmetry of the Pc complexes. The five - level model rate equations were used to determine the two photon absorption, excited state absorption and ground state absorption cross sections of the synthesized complexes. The z inc A 3 B type asymmetrical Pc complexes gave the largest two photon absorption and 휎 푒 / 휎 푔 ratio values. This Pc complex could be used in future work to enhance the nonlinear response further by introducing nanomaterials and converting the Pc complex to a binuclear Pc. This work also reports on the density functional theory (DFT) calculations o f dipolar/octupolar contributions in order to study the first order hyperpolarizability of the synthesized Pc complexes.
- Full Text:
- Authors: Mugeza, Rhulani Donney
- Date: 2021
- Subjects: Spectrum analysis , Mass spectrometry , Phthalocyanines
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/171667 , vital:42108
- Description: This work reports on the synthesis of symmetrical and asymmetrical A 3 B type metal free, cobalt and zinc Phthalocyanines (Pc) .A wide range of spectroscopic techniques such as Uv - visible absorption (UV), magnetic circular dichroism (MCD), mass spectrometry, elemental analysis, IR spectroscopy and time correlated single photo n counting spectroscopy (TCSPC) have been used to study the spectroscopic properties of the phthalocyanine complexes. The Z - scan technique was used to comparatively investigate the nonlinear absorption coefficient ( 휷 ) and the nonlinear refraction index ( 풏 ퟐ ) of the synthesized complexes. The following trend was obtained for the synthesized Pc’s in terms of the 휷 values 7.25 × 10 − 10 ( 4b ) > 3.76 × 10 − 10 ( 4a ) > 3.52 × 10 − 10 ( 4c ) > 2.29 × 10 − 10 ( 3c ) > 1.68 × 10 − 10 ( 3a ) > 1.65 × 10 − 10 ( 3b ) mW - 1 . The 휷 values trend of synthesized Pc complexes show that the asymmetrical A 3 B type metal free, cobalt and zinc Pc complexes ( 4a , 4b and 4c ) have larger 휷 values as compared to the octa - substituted symmetrical metal free, cobalt and zinc Pc complexes ( 3a , 3b and 3c ) which is attributed to the low symmetry of the Pc complexes. The five - level model rate equations were used to determine the two photon absorption, excited state absorption and ground state absorption cross sections of the synthesized complexes. The z inc A 3 B type asymmetrical Pc complexes gave the largest two photon absorption and 휎 푒 / 휎 푔 ratio values. This Pc complex could be used in future work to enhance the nonlinear response further by introducing nanomaterials and converting the Pc complex to a binuclear Pc. This work also reports on the density functional theory (DFT) calculations o f dipolar/octupolar contributions in order to study the first order hyperpolarizability of the synthesized Pc complexes.
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Synthesis, theoretical calculations and laser flash photolysis studies of selected amphiphilic porphyrin derivatives used as biofilm photodegradative materials
- Openda, Yolande I, Ngoy, Bokolombe P, Muva, Jules T, Nyokong, Tebello
- Authors: Openda, Yolande I , Ngoy, Bokolombe P , Muva, Jules T , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190589 , vital:45008 , xlink:href="https://doi.org/10.1039/D1NJ02651H"
- Description: Photodynamic antimicrobial activities of gallium and indium porphyrins as well as their quaternized derivatives have been investigated against S. aureus and E. coli biofilms, as well as on their planktonic (free floating) cells using a light emitting diode lamp at 415 nm. The studied photosensitizers show considerable ability to generate singlet oxygen and the quaternized molecules 2a and 3a are potential photodynamic antimicrobial chemotherapy (PACT) agents with log10 colony forming units >9 for E. coli and S. aureus planktonic cells. The quaternized derivatives are found to have higher ability to significantly suppress the biofilms of both S. aureus and E. coli in vitro. Therefore, this demonstrates that they are potentially suitable photosensitive agents for PACT use. The TD-B3LYP/LanL2DZ calculations were performed to evaluate the singlet excitation energies of quaternized and non-quaternized porphyrins in vacuo. Our study shows excellent agreement between time-dependent density-functional theory (TD-DFT) excited energies and experimental S1 > S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-visible spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO−1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states.
- Full Text:
- Authors: Openda, Yolande I , Ngoy, Bokolombe P , Muva, Jules T , Nyokong, Tebello
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/190589 , vital:45008 , xlink:href="https://doi.org/10.1039/D1NJ02651H"
- Description: Photodynamic antimicrobial activities of gallium and indium porphyrins as well as their quaternized derivatives have been investigated against S. aureus and E. coli biofilms, as well as on their planktonic (free floating) cells using a light emitting diode lamp at 415 nm. The studied photosensitizers show considerable ability to generate singlet oxygen and the quaternized molecules 2a and 3a are potential photodynamic antimicrobial chemotherapy (PACT) agents with log10 colony forming units >9 for E. coli and S. aureus planktonic cells. The quaternized derivatives are found to have higher ability to significantly suppress the biofilms of both S. aureus and E. coli in vitro. Therefore, this demonstrates that they are potentially suitable photosensitive agents for PACT use. The TD-B3LYP/LanL2DZ calculations were performed to evaluate the singlet excitation energies of quaternized and non-quaternized porphyrins in vacuo. Our study shows excellent agreement between time-dependent density-functional theory (TD-DFT) excited energies and experimental S1 > S0 excitation energies. The small deviation observed between the calculated and experimental spectra arises from the solvent effect. The excitation energies observed in these UV-visible spectra mostly originated from electron promotion between the highest occupied molecular orbital (HOMO) for the less intense band and the HOMO−1 for the most intense band of the ground states to the lower unoccupied molecular orbital (LUMO) of the excited states.
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Tapping the role of microbial biosurfactants in pesticide remediation: an eco-friendly approach for environmental sustainability
- Raj, Aman, Kumar, Ashwani, Dames, Joanna F
- Authors: Raj, Aman , Kumar, Ashwani , Dames, Joanna F
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440430 , vital:73782 , https://doi.org/10.3389/fmicb.2021.791723
- Description: Pesticides are used indiscriminately all over the world to protect crops from pests and pathogens. If they are used in excess, they contaminate the soil and water bodies and negatively affect human health and the environment. However, bioremediation is the most viable option to deal with these pollutants, but it has certain limitations. Therefore, harnessing the role of microbial biosurfactants in pesticide remediation is a promising approach. Biosurfactants are the amphiphilic compounds that can help to increase the bioavailability of pesticides, and speeds up the bioremediation process. Biosurfactants lower the surface area and interfacial tension of immiscible fluids and boost the solubility and sorption of hydrophobic pesticide contaminants. They have the property of biodegradability, low toxicity, high selectivity, and broad action spectrum under extreme pH, temperature, and salinity conditions, as well as a low critical micelle concentration (CMC). All these factors can augment the process of pesticide remediation. Application of metagenomic and in-silico tools would help by rapidly characterizing pesticide degrading microorganisms at a taxonomic and functional level. A comprehensive review of the literature shows that the role of biosurfactants in the biological remediation of pesticides has received limited attention. Therefore, this article is intended to provide a detailed overview of the role of various biosurfactants in improving pesticide remediation as well as different methods used for the detection of microbial biosurfactants. Additionally, this article covers the role of advanced metagenomics tools in characterizing the biosurfactant producing pesticide degrading microbes from different environments.
- Full Text:
- Authors: Raj, Aman , Kumar, Ashwani , Dames, Joanna F
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440430 , vital:73782 , https://doi.org/10.3389/fmicb.2021.791723
- Description: Pesticides are used indiscriminately all over the world to protect crops from pests and pathogens. If they are used in excess, they contaminate the soil and water bodies and negatively affect human health and the environment. However, bioremediation is the most viable option to deal with these pollutants, but it has certain limitations. Therefore, harnessing the role of microbial biosurfactants in pesticide remediation is a promising approach. Biosurfactants are the amphiphilic compounds that can help to increase the bioavailability of pesticides, and speeds up the bioremediation process. Biosurfactants lower the surface area and interfacial tension of immiscible fluids and boost the solubility and sorption of hydrophobic pesticide contaminants. They have the property of biodegradability, low toxicity, high selectivity, and broad action spectrum under extreme pH, temperature, and salinity conditions, as well as a low critical micelle concentration (CMC). All these factors can augment the process of pesticide remediation. Application of metagenomic and in-silico tools would help by rapidly characterizing pesticide degrading microorganisms at a taxonomic and functional level. A comprehensive review of the literature shows that the role of biosurfactants in the biological remediation of pesticides has received limited attention. Therefore, this article is intended to provide a detailed overview of the role of various biosurfactants in improving pesticide remediation as well as different methods used for the detection of microbial biosurfactants. Additionally, this article covers the role of advanced metagenomics tools in characterizing the biosurfactant producing pesticide degrading microbes from different environments.
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Teacher Contexts as Amplifiers and Filters to Environmental Pedagogical Content Knowledge within a Professional Development System
- Brundrit, Susan, Schudel, Ingrid J
- Authors: Brundrit, Susan , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435141 , vital:73133 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The chapter draws on the contextual work underpinning a broader study that aimed to understand how environmental pedagogical content knowledge is supported and constructed in the Fundisa for Change teacher professional development (TPD) courses (Brundrit 2018). Necessary to this was an understanding of the contextual realities (amplifiers and filters) of the system in which the course occurs, leading to the question: How do school and classroom contexts act to amplify and filter the environmental pedagogical content knowledge learning of teachers in a teacher professional development programme?.
- Full Text:
- Authors: Brundrit, Susan , Schudel, Ingrid J
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435141 , vital:73133 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: The chapter draws on the contextual work underpinning a broader study that aimed to understand how environmental pedagogical content knowledge is supported and constructed in the Fundisa for Change teacher professional development (TPD) courses (Brundrit 2018). Necessary to this was an understanding of the contextual realities (amplifiers and filters) of the system in which the course occurs, leading to the question: How do school and classroom contexts act to amplify and filter the environmental pedagogical content knowledge learning of teachers in a teacher professional development programme?.
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Teacher Professional Development in Environment and Sustainability Education
- Songqwaru, Zintle, Tshiningayamwe, Sirkka
- Authors: Songqwaru, Zintle , Tshiningayamwe, Sirkka
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435248 , vital:73142 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: No education policy, no matter how well designed, can succeed without a teacher (Sanyal 2013). Additionally, a change in policy alone is not sufficient to improve an education system (Livingstone 2012), no matter how well meaning. The quality of teachers’ professional practices determines to some extent the quality of teaching and learning in the schooling sector. Teacher quality, and not only teacher supply, is important for learning; hence, teacher professional development should be a priority in all education and development strategies (Unesco 2015a).
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- Authors: Songqwaru, Zintle , Tshiningayamwe, Sirkka
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/435248 , vital:73142 , ISBN 9781928502241 , https://library.oapen.org/handle/20.500.12657/64082
- Description: No education policy, no matter how well designed, can succeed without a teacher (Sanyal 2013). Additionally, a change in policy alone is not sufficient to improve an education system (Livingstone 2012), no matter how well meaning. The quality of teachers’ professional practices determines to some extent the quality of teaching and learning in the schooling sector. Teacher quality, and not only teacher supply, is important for learning; hence, teacher professional development should be a priority in all education and development strategies (Unesco 2015a).
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