Fluorescence behaviour of supramolecular hybrids containing graphene quantum dots and pyrene-derivatized phthalocyanines and porphyrins
- Achadu, Ojodomo John, Managa, Muthumuni, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Managa, Muthumuni , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188953 , vital:44801 , xlink:href="https://doi.org/10.1016/j.jphotochem.2016.10.029"
- Description: Novel pyrene-derivatized zinc and cobalt phthalocyanines (Pcs) and porphyrins (Ps) were immobilized on graphene quantum dots (GQDs) to form GQDs-Pcs and GQDs-Ps supramolecular hybrids via the π–π stacking interaction method. Spectroscopic evidence shows that the resultant hybrids were stable owing to the strong π–π stacking interaction between the GQDs and the respective Pcs and Ps, thus leading to the fabrication of interesting and functional supramolecular hybrids by taking advantage of the delocalized π electron systems of GQDs and the macrocycles. The conjugates showed increased fluorescence quantum yields for the Pcs/Ps, but decreased values for the GQDs in the conjugates. These novel hybrid materials could potentially be deployed for studies in both fundamental and applied perspectives due to the synergistic contributions resulting from the combination of their excellent electronic and optical properties.
- Full Text:
- Date Issued: 2017
Application of graphene quantum dots functionalized with thymine and thymine-appended zinc phthalocyanine as novel photoluminescent nanoprobes
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188508 , vital:44760 , xlink:href="https://doi.org/10.1039/C6NJ03285K"
- Description: Graphene quantum dots (GQDs) and zinc phthalocyanine (ZnPc) were separately modified with thymine to obtain thymine-functionalized GQDs (T-GQDs) and ZnPc (T-ZnPc). T-GQDs and nanoconjugates of T-ZnPc with pristine GQDs (represented as pristine GQDs–T-ZnPc) or T-GQDs (represented as T-GQDs–T-ZnPc) were employed as fluorescent probes for the detection of mercury(II) ions (Hg2+). The as-synthesized T-GQDs alone demonstrated a highly sensitive and selective fluorescence “turn-OFF” process for Hg2+ detection due to the specific interaction between the thymine functionality on the T-GQDs with Hg2+. On the other hand, the fluorescence of pristine GQDs and T-GQDs was quenched (“turn-OFF”) upon coordination with T-ZnPc. However, the fluorescence emission was selectively restored (“turn-ON” process) in the presence of Hg2+ resulting in the sensitive detection of Hg2+ in the nanomolar concentration range (limit of detection = 0.05 nM, for the pristine GQDs–T-ZnPc probe). The probe containing pristine GQDs and the T-ZnPc complex demonstrated a higher specific and sensitive recognition of Hg2+ as compared to the T-GQDs alone or T-GQDs–T-ZnPc probes which are ascribed to the fluorescence “turn-ON” process of the former. Screening of different metal ions and counter ions proved that the probes are specifically suited for Hg2+ detection.
- Full Text:
- Date Issued: 2017
Graphene quantum dots decorated with maleimide and zinc tetramaleimido-phthalocyanine: Application in the design of “OFF-ON” fluorescence sensors for biothiols
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188282 , vital:44741 , xlink:href="https://doi.org/10.1016/j.talanta.2017.01.031"
- Description: The fabrication of maleimide-derivatized graphene quantum dots (M-GQDs) and zinc phthalocyanine (2) as novel sensor probes for the selective detection of biothiols (cysteine, homocysteine or glutathione) through the rapid and specific Michael addition reaction between biothiols and the maleimide-derivatized probes is presented in this study. GQDs directly functionalized with maleimide units (M-GQDs) were synthesized and deployed for biothiols recognition following the principle of Michael addition. M-GQDs probe was found to be highly sensitive and selective towards biothiols detection in the nanomolar range in aqueous solution and at physiological pH (7.0). On the other hand, non-covalent interaction between pristine GQDs and novel zinc tetramaleimido-derivatized phthalocyanine resulted in the quenching of the pristine GQDs fluorescence emission which was switched back to the “ON” mode by Michael addition mechanism in the presence of biothiols. Tested relevant biomolecules did not interfere in the quantitative recognition of the biothiols. The probes showed to be highly sensitive, specific and selective for biothiols sensing in simulated real samples.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188282 , vital:44741 , xlink:href="https://doi.org/10.1016/j.talanta.2017.01.031"
- Description: The fabrication of maleimide-derivatized graphene quantum dots (M-GQDs) and zinc phthalocyanine (2) as novel sensor probes for the selective detection of biothiols (cysteine, homocysteine or glutathione) through the rapid and specific Michael addition reaction between biothiols and the maleimide-derivatized probes is presented in this study. GQDs directly functionalized with maleimide units (M-GQDs) were synthesized and deployed for biothiols recognition following the principle of Michael addition. M-GQDs probe was found to be highly sensitive and selective towards biothiols detection in the nanomolar range in aqueous solution and at physiological pH (7.0). On the other hand, non-covalent interaction between pristine GQDs and novel zinc tetramaleimido-derivatized phthalocyanine resulted in the quenching of the pristine GQDs fluorescence emission which was switched back to the “ON” mode by Michael addition mechanism in the presence of biothiols. Tested relevant biomolecules did not interfere in the quantitative recognition of the biothiols. The probes showed to be highly sensitive, specific and selective for biothiols sensing in simulated real samples.
- Full Text:
- Date Issued: 2017
Graphene quantum dots coordinated to mercaptopyridine-substituted phthalocyanines: Characterization and application as fluorescence “turn ON” nanoprobes
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188293 , vital:44742 , xlink:href="https://doi.org/10.1016/j.saa.2016.11.043"
- Description: This study reports on the design of novel nanoconjugates of graphene quantum dots (GQDs) and tetra or octa-mercaptopyridine-substituted zinc and aluminium phthalocyanines (Pcs) deployed as fluorescence “turn ON” nanoprobes. The phthalocyanines were separately adsorbed onto the planar structure of graphene quantum dots (GQDs) via π-π stacking interaction to form GQDs-mercaptopyridine Pcs nanoconjugates. The quaternized Pc complexes could also interact with the GQDs through electrostatic attraction due to the positive charges on the Pcs ring substituents and the negative charges on the surface of GQDs. The fluorescence emission of the GQDs was quenched upon coordination to the respective Pcs. However, the fluorescence emission was “turned ON” in the presence of Hg2 + employed as a test analyte. The mechanism of the “turn ON” of the GQDs emission in the nanoconjugates is ascribed to the strong affinity of Hg2 + to bind with the bridging sulfur on the Pcs periphery thereby disrupting the π-π stacking interaction between the GQDs and the Pcs with a consequent “turn ON” of the coordinated GQDs' fluorescence.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188293 , vital:44742 , xlink:href="https://doi.org/10.1016/j.saa.2016.11.043"
- Description: This study reports on the design of novel nanoconjugates of graphene quantum dots (GQDs) and tetra or octa-mercaptopyridine-substituted zinc and aluminium phthalocyanines (Pcs) deployed as fluorescence “turn ON” nanoprobes. The phthalocyanines were separately adsorbed onto the planar structure of graphene quantum dots (GQDs) via π-π stacking interaction to form GQDs-mercaptopyridine Pcs nanoconjugates. The quaternized Pc complexes could also interact with the GQDs through electrostatic attraction due to the positive charges on the Pcs ring substituents and the negative charges on the surface of GQDs. The fluorescence emission of the GQDs was quenched upon coordination to the respective Pcs. However, the fluorescence emission was “turned ON” in the presence of Hg2 + employed as a test analyte. The mechanism of the “turn ON” of the GQDs emission in the nanoconjugates is ascribed to the strong affinity of Hg2 + to bind with the bridging sulfur on the Pcs periphery thereby disrupting the π-π stacking interaction between the GQDs and the Pcs with a consequent “turn ON” of the coordinated GQDs' fluorescence.
- Full Text:
- Date Issued: 2017
Graphene quantum dots anchored onto mercaptopyridine-substituted zinc phthalocyanine-Au@ Ag nanoparticle hybrid: Application as fluorescence “off-on-off” sensor for Hg2+ and biothiols
- Achadu, Ojodomo John, Nyokong, Tebello
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188194 , vital:44731 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.06.002"
- Description: Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.
- Full Text:
- Date Issued: 2017
- Authors: Achadu, Ojodomo John , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188194 , vital:44731 , xlink:href="https://doi.org/10.1016/j.dyepig.2017.06.002"
- Description: Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.
- Full Text:
- Date Issued: 2017
Photophysical properties of a series of alloyed and non-alloyed water-soluble l-cysteine-capped core quantum dots
- Adegoke, Oluwasesan, Nyokong, Tebello, Forbes, Patricia B
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188486 , vital:44758 , xlink:href="https://doi.org/10.1016/j.jallcom.2016.10.276"
- Description: Photophysical properties of quantum dots (QDs) such as their photoluminescence (PL) quantum yield (QY), exciton lifetime and PL stability are important parameters used to unravel their chemical and physical characteristics. In this work, we have comparatively investigated the photophysical properties of a series of L-cysteine-capped non-alloyed (CdTe and CdSe) and alloyed (CdZnTe, CdSeS, CdSeTe and CdSeTeS) core QDs. Each of the QDs varied in their size and PL emission wavelength. We observe no physical relationship between the PL QY of the QDs and their PL stability. Based on the PL stability assessment, CdTe QDs with a high PL QY value of 88% exhibited poor PL stability while moderate PL stability was observed for CdZnTe (QY = 78%); CdSe (QY = 3%); and CdSeTe QDs (QY = ∼3%). Alloyed CdSeS (QY = ∼69%) and CdSeTeS (QY = 23%) QDs exhibited good PL stability and can serve as potential fluorophores for a wide range of chemical and biological applications. Generally, it is proposed that the structural nature of the QDs played a significant role in their overall photophysical properties. The information provided in this work will assist in the selection of core QDs suitable for different applications.
- Full Text:
- Date Issued: 2017
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello , Forbes, Patricia B
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188486 , vital:44758 , xlink:href="https://doi.org/10.1016/j.jallcom.2016.10.276"
- Description: Photophysical properties of quantum dots (QDs) such as their photoluminescence (PL) quantum yield (QY), exciton lifetime and PL stability are important parameters used to unravel their chemical and physical characteristics. In this work, we have comparatively investigated the photophysical properties of a series of L-cysteine-capped non-alloyed (CdTe and CdSe) and alloyed (CdZnTe, CdSeS, CdSeTe and CdSeTeS) core QDs. Each of the QDs varied in their size and PL emission wavelength. We observe no physical relationship between the PL QY of the QDs and their PL stability. Based on the PL stability assessment, CdTe QDs with a high PL QY value of 88% exhibited poor PL stability while moderate PL stability was observed for CdZnTe (QY = 78%); CdSe (QY = 3%); and CdSeTe QDs (QY = ∼3%). Alloyed CdSeS (QY = ∼69%) and CdSeTeS (QY = 23%) QDs exhibited good PL stability and can serve as potential fluorophores for a wide range of chemical and biological applications. Generally, it is proposed that the structural nature of the QDs played a significant role in their overall photophysical properties. The information provided in this work will assist in the selection of core QDs suitable for different applications.
- Full Text:
- Date Issued: 2017
Beyond health care providers’recommendations: understandinginfluences on infant feeding choices ofwomen with HIV in the Eastern Cape,South Africa
- Adeniyi, Oladele Vincent, Ajayi, Anthony Idowu, Issah, Moshood, Owolabi, Eyitayo Omolara, Ter Goon, Daniel, Avramovic, Gordana, Lambert, John
- Authors: Adeniyi, Oladele Vincent , Ajayi, Anthony Idowu , Issah, Moshood , Owolabi, Eyitayo Omolara , Ter Goon, Daniel , Avramovic, Gordana , Lambert, John
- Date: 2017
- Subjects: Africa Infant Feeding Sub-sahara
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6063 , vital:45109 , https://doi.org/10.1186/s13006-019-0201-5
- Description: Background: Despite the array of studies on infant feeding practices of HIV-infected women, gaps still exist in the understanding of the underlying reasons for their infant feeding choices. Potential for behavioural change exists, especially in the light of the 2016 updated World Health Organization guideline on HIV and infant feeding. The aim of this paper is to determine the rate of adoption of exclusive breastfeeding in this cohort, examine the determinants of infant feeding choices of HIV-infected women and assess the underlying reasons for these choices. Methods: This was a mixed methods study conducted between September 2015 and May 2016. It analyses the quantitative and qualitative data of 1662 peripartum women enrolled in the East London Prospective Cohort Study across three large maternity services in the Eastern Cape. Women with HIV reported their preferred choices of infant feeding. In addition, participants explained the underlying reasons for their choices. Descriptive and inferential statistics summarised the quantitative data, while thematic content analysis was performed on qualitative data. Results: Of the 1662 women with complete responses, 80.3% opted to exclusively breastfeed their babies. In the adjusted model, up to grade 12 education level (AOR: 1.81; 95% CI: 1.14, 2.86), rural/peri-urban residence (AOR:1.44; 95% CI: 1.05, 1.96), alcohol use (AOR: 1.65; 95% CI: 1.25, 2.18), negative or unknown HIV status at booking (AOR:1.85; 95% CI:1.27, 2.70), currently married (AOR:1.43; 95% CI:1.01, 2.02) and WHO Clinical Stage 2–4 (AOR:1.77; 95% CI: 1.15, 2.72) were significantly associated with the decision to exclusively breastfeed. Health care providers’ recommendations, perceived benefits of breastfeeding, unaffordability of formula feeding, and coercion were the underlying reasons for wanting to breastfeed; while work/school-related demands, breast-related issues, and fear of infecting the baby influenced their decision to formula feed. Conclusion: The majority of HIV-infected women chose to breastfeed their babies in the Eastern Cape. Following up on these women to ensure they breastfeed exclusively, while also addressing their possible concerns, could be an important policy intervention. Future studies should focus on how early infant feeding decisions change over time, as well as the health outcomes for mother and child. Keywords: Exclusive breastfeeding, Infant feeding practice, infant formula feeding, HIV-infected peripartum women, South Africa, WHO guideline
- Full Text:
- Date Issued: 2017
- Authors: Adeniyi, Oladele Vincent , Ajayi, Anthony Idowu , Issah, Moshood , Owolabi, Eyitayo Omolara , Ter Goon, Daniel , Avramovic, Gordana , Lambert, John
- Date: 2017
- Subjects: Africa Infant Feeding Sub-sahara
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6063 , vital:45109 , https://doi.org/10.1186/s13006-019-0201-5
- Description: Background: Despite the array of studies on infant feeding practices of HIV-infected women, gaps still exist in the understanding of the underlying reasons for their infant feeding choices. Potential for behavioural change exists, especially in the light of the 2016 updated World Health Organization guideline on HIV and infant feeding. The aim of this paper is to determine the rate of adoption of exclusive breastfeeding in this cohort, examine the determinants of infant feeding choices of HIV-infected women and assess the underlying reasons for these choices. Methods: This was a mixed methods study conducted between September 2015 and May 2016. It analyses the quantitative and qualitative data of 1662 peripartum women enrolled in the East London Prospective Cohort Study across three large maternity services in the Eastern Cape. Women with HIV reported their preferred choices of infant feeding. In addition, participants explained the underlying reasons for their choices. Descriptive and inferential statistics summarised the quantitative data, while thematic content analysis was performed on qualitative data. Results: Of the 1662 women with complete responses, 80.3% opted to exclusively breastfeed their babies. In the adjusted model, up to grade 12 education level (AOR: 1.81; 95% CI: 1.14, 2.86), rural/peri-urban residence (AOR:1.44; 95% CI: 1.05, 1.96), alcohol use (AOR: 1.65; 95% CI: 1.25, 2.18), negative or unknown HIV status at booking (AOR:1.85; 95% CI:1.27, 2.70), currently married (AOR:1.43; 95% CI:1.01, 2.02) and WHO Clinical Stage 2–4 (AOR:1.77; 95% CI: 1.15, 2.72) were significantly associated with the decision to exclusively breastfeed. Health care providers’ recommendations, perceived benefits of breastfeeding, unaffordability of formula feeding, and coercion were the underlying reasons for wanting to breastfeed; while work/school-related demands, breast-related issues, and fear of infecting the baby influenced their decision to formula feed. Conclusion: The majority of HIV-infected women chose to breastfeed their babies in the Eastern Cape. Following up on these women to ensure they breastfeed exclusively, while also addressing their possible concerns, could be an important policy intervention. Future studies should focus on how early infant feeding decisions change over time, as well as the health outcomes for mother and child. Keywords: Exclusive breastfeeding, Infant feeding practice, infant formula feeding, HIV-infected peripartum women, South Africa, WHO guideline
- Full Text:
- Date Issued: 2017
Omics-based molecular techniques in oral pathology centred cancer: prospect and challenges in Africa
- Adeola, Henry A., Soyele, Olujide.O., Adefuye, Anthonio O., Jimoh, Sikiru A., Butali, Azeez
- Authors: Adeola, Henry A. , Soyele, Olujide.O. , Adefuye, Anthonio O. , Jimoh, Sikiru A. , Butali, Azeez
- Date: 2017
- Subjects: Eastern Cape, South Africa Oral mucosa--Cancer Oral Pathology Cancer Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5857 , vital:44658 , https://DOI10.1186/s12935-017-0432-8
- Description: Background:The completion of the human genome project and the accomplished milestones in the human proteome project; as well as the progress made so far in computational bioinformatics and “big data” processing have contributed immensely to individualized/personalized medicine in the developed world.Main body:At the dawn of precision medicine, various omics-based therapies and bioengineering can now be applied accurately for the diagnosis, prognosis, treatment, and risk stratification of cancer in a manner that was hitherto not thought possible. The widespread introduction of genomics and other omics-based approaches into the postgraduate training curriculum of diverse medical and dental specialties, including pathology has improved the proficiency of practitioners in the use of novel molecular signatures in patient management. In addition, intricate details about disease disparity among different human populations are beginning to emerge. This would facilitate the use of tailor-made novel theranostic methods based on emerging molecular evidences.Conclusion:In this review, we examined the challenges and prospects of using currently available omics-based technologies vis-à-vis oral pathology as well as prompt cancer diagnosis and treatment in a resource limited setting.Keywords:Omics-based, Molecular, Developing world, Oral pathology, Challenges
- Full Text:
- Date Issued: 2017
Omics-based molecular techniques in oral pathology centred cancer: prospect and challenges in Africa
- Authors: Adeola, Henry A. , Soyele, Olujide.O. , Adefuye, Anthonio O. , Jimoh, Sikiru A. , Butali, Azeez
- Date: 2017
- Subjects: Eastern Cape, South Africa Oral mucosa--Cancer Oral Pathology Cancer Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/5857 , vital:44658 , https://DOI10.1186/s12935-017-0432-8
- Description: Background:The completion of the human genome project and the accomplished milestones in the human proteome project; as well as the progress made so far in computational bioinformatics and “big data” processing have contributed immensely to individualized/personalized medicine in the developed world.Main body:At the dawn of precision medicine, various omics-based therapies and bioengineering can now be applied accurately for the diagnosis, prognosis, treatment, and risk stratification of cancer in a manner that was hitherto not thought possible. The widespread introduction of genomics and other omics-based approaches into the postgraduate training curriculum of diverse medical and dental specialties, including pathology has improved the proficiency of practitioners in the use of novel molecular signatures in patient management. In addition, intricate details about disease disparity among different human populations are beginning to emerge. This would facilitate the use of tailor-made novel theranostic methods based on emerging molecular evidences.Conclusion:In this review, we examined the challenges and prospects of using currently available omics-based technologies vis-à-vis oral pathology as well as prompt cancer diagnosis and treatment in a resource limited setting.Keywords:Omics-based, Molecular, Developing world, Oral pathology, Challenges
- Full Text:
- Date Issued: 2017
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61435 , vital:28026 , https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5209310/
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
Improved endoglucanase production and mycelial biomass of some ericoid fungi
- Adeoyo, Olusegun R, Pletschke, Brett I, Dames, Joanna F
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
- Authors: Adeoyo, Olusegun R , Pletschke, Brett I , Dames, Joanna F
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440352 , vital:73776 , https://doi.org/10.1186/s13568-016-0312-y
- Description: Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endophytic fungal isolates. Out of the five fungal isolates screened, Leohumicola sp. (ChemRU330/PPRI 13195) had the highest relative enzyme activity and was tested along with isolates belonging to Hyloscyphaceae (EdRU083/PPRI 17284) and Leotiomycetes (EdRU002/PPRI 17261) for endoglucanase production under different pH and nutritional conditions that included: carbon sources, nitrogen sources and metal ions, at an optimum temperature of 28 °C. An optimal of pH 5.0 produced enzyme activity of 3.99, 2.18 and 4.31 (U/mg protein) for isolates EdRU083, EdRU002 and Leohumicola sp. respectively. Increased enzyme activities and improved mycelial biomass production were obtained in the presence of supplements such as potassium, sodium, glucose, maltose, cellobiose, tryptone and peptone. While NaFe-EDTA and Co2+ inhibited enzyme activity. The potential role of these fungi as a source of novel enzymes is an ongoing objective of this study.
- Full Text:
- Date Issued: 2017
Synthesis and anti-parasitic activity of C-benzylated (N-arylcarbamoyl) alkylphosphonate esters
- Adeyemi, Christiana Modupe, Isaacs, Michelle, Mnkandhla, Dumisani, Krause, Rui W M, Klein, Rosalyn, Hoppe, Heinrich C, Lobb, Kevin A, Kaye, Perry T
- Authors: Adeyemi, Christiana Modupe , Isaacs, Michelle , Mnkandhla, Dumisani , Krause, Rui W M , Klein, Rosalyn , Hoppe, Heinrich C , Lobb, Kevin A , Kaye, Perry T
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125641 , vital:35803 , https://doi.org/10.1016/j.tet.2017.01.045
- Description: Unexpected substituent-dependent regioselectivty challenges in the synthesis of C-benzylated (N-arylcarbamoyl)phosphonate esters have been resolved. The C-benzylated N-furfurylcarbamoyl derivative showed low micromolar PfLDH inhibition, while one of the C-benzylated N-arylcarbamoyl analogues was active against Nagana Trypanosoma brucei parasites which are responsible for African trypanosomiasis in cattle.
- Full Text:
- Date Issued: 2017
- Authors: Adeyemi, Christiana Modupe , Isaacs, Michelle , Mnkandhla, Dumisani , Krause, Rui W M , Klein, Rosalyn , Hoppe, Heinrich C , Lobb, Kevin A , Kaye, Perry T
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125641 , vital:35803 , https://doi.org/10.1016/j.tet.2017.01.045
- Description: Unexpected substituent-dependent regioselectivty challenges in the synthesis of C-benzylated (N-arylcarbamoyl)phosphonate esters have been resolved. The C-benzylated N-furfurylcarbamoyl derivative showed low micromolar PfLDH inhibition, while one of the C-benzylated N-arylcarbamoyl analogues was active against Nagana Trypanosoma brucei parasites which are responsible for African trypanosomiasis in cattle.
- Full Text:
- Date Issued: 2017
Extended use of grey water for irrigating home gardens in an arid environment
- Al-Ismaili, Abdulrahim M, Ahmed, Mushtaque, Al-Busaidi, Ahmed, Al-Adawi, Seif, Tandlich, Roman, Al-Amri, Mohammed
- Authors: Al-Ismaili, Abdulrahim M , Ahmed, Mushtaque , Al-Busaidi, Ahmed , Al-Adawi, Seif , Tandlich, Roman , Al-Amri, Mohammed
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76048 , vital:30497 , https://doi.org/10.1007/s11356-017-8963-z
- Description: The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
- Full Text:
- Date Issued: 2017
- Authors: Al-Ismaili, Abdulrahim M , Ahmed, Mushtaque , Al-Busaidi, Ahmed , Al-Adawi, Seif , Tandlich, Roman , Al-Amri, Mohammed
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76048 , vital:30497 , https://doi.org/10.1007/s11356-017-8963-z
- Description: The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
- Full Text:
- Date Issued: 2017
Improving fold resistance prediction of HIV-1 against protease and reverse transcriptase inhibitors using artificial neural networks:
- Amamuddy, Olivier S, Bishop, Nigel T, Tastan Bishop, Özlem
- Authors: Amamuddy, Olivier S , Bishop, Nigel T , Tastan Bishop, Özlem
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148261 , vital:38724 , https://0-doi.org.wam.seals.ac.za/10.1186/s12859-017-1782-x
- Description: Drug resistance in HIV treatment is still a worldwide problem. Predicting resistance to antiretrovirals (ARVs) before starting any treatment is important. Prediction accuracy is essential, as low-accuracy predictions increase the risk of prescribing sub-optimal drug regimens leading to patients developing resistance sooner. Artificial Neural Networks (ANNs) are a powerful tool that would be able to assist in drug resistance prediction. In this study, we constrained the dataset to subtype B, sacrificing generalizability for a higher predictive performance, and demonstrated that the predictive quality of the ANN regression models have definite improvement for most ARVs.
- Full Text:
- Date Issued: 2017
- Authors: Amamuddy, Olivier S , Bishop, Nigel T , Tastan Bishop, Özlem
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148261 , vital:38724 , https://0-doi.org.wam.seals.ac.za/10.1186/s12859-017-1782-x
- Description: Drug resistance in HIV treatment is still a worldwide problem. Predicting resistance to antiretrovirals (ARVs) before starting any treatment is important. Prediction accuracy is essential, as low-accuracy predictions increase the risk of prescribing sub-optimal drug regimens leading to patients developing resistance sooner. Artificial Neural Networks (ANNs) are a powerful tool that would be able to assist in drug resistance prediction. In this study, we constrained the dataset to subtype B, sacrificing generalizability for a higher predictive performance, and demonstrated that the predictive quality of the ANN regression models have definite improvement for most ARVs.
- Full Text:
- Date Issued: 2017
Biological and geophysical feedbacks with fire in the Earth System
- Archibald, S, Lehmann, C E, Belcher, C, Bond, W J, Bradstock, R A, Daniau, A L, Dexter, K, Forrestel, E J, Greve, M, He, T, Higgins, Simon I, Ripley, Bradford S
- Authors: Archibald, S , Lehmann, C E , Belcher, C , Bond, W J , Bradstock, R A , Daniau, A L , Dexter, K , Forrestel, E J , Greve, M , He, T , Higgins, Simon I , Ripley, Bradford S
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61413 , vital:28024 , http://iopscience.iop.org/article/10.1088/1748-9326/aa9ead/meta
- Description: Roughly 3% of the Earth’s land surface burns annually, representing a critical exchange of energy and matter between the land and atmosphere via combustion. Fires range from slow smouldering peat fires, to low-intensity surface fires, to intense crown fires, depending on vegetation structure, fuel moisture, prevailing climate, and weather conditions. While the links between biogeochemistry, climate and fire are widely studied within Earth system science, these relationships are also mediated by fuels – namely plants and their litter – which are the product of evolutionary and ecological processes. Fire is a powerful selective force and, over their evolutionary history, plants across diverse clades have evolved numerous traits that either tolerate or promote fire. Here we outline a conceptual framework of how plant traits determine the flammability of ecosystems and interact with climate and weather to influence fire regimes. We explore how these evolutionary and ecological processes scale to impact biogeochemistry and Earth system processes. Finally, we outline several research challenges that, when resolved, will improve our understanding of the role of plant evolution in mediating the fire feedbacks driving Earth system processes. Understanding current patterns of fire and vegetation, as well as patterns of fire over geological time, requires research that incorporates evolutionary biology, ecology, biogeography, and the biogeosciences.
- Full Text:
- Date Issued: 2017
- Authors: Archibald, S , Lehmann, C E , Belcher, C , Bond, W J , Bradstock, R A , Daniau, A L , Dexter, K , Forrestel, E J , Greve, M , He, T , Higgins, Simon I , Ripley, Bradford S
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61413 , vital:28024 , http://iopscience.iop.org/article/10.1088/1748-9326/aa9ead/meta
- Description: Roughly 3% of the Earth’s land surface burns annually, representing a critical exchange of energy and matter between the land and atmosphere via combustion. Fires range from slow smouldering peat fires, to low-intensity surface fires, to intense crown fires, depending on vegetation structure, fuel moisture, prevailing climate, and weather conditions. While the links between biogeochemistry, climate and fire are widely studied within Earth system science, these relationships are also mediated by fuels – namely plants and their litter – which are the product of evolutionary and ecological processes. Fire is a powerful selective force and, over their evolutionary history, plants across diverse clades have evolved numerous traits that either tolerate or promote fire. Here we outline a conceptual framework of how plant traits determine the flammability of ecosystems and interact with climate and weather to influence fire regimes. We explore how these evolutionary and ecological processes scale to impact biogeochemistry and Earth system processes. Finally, we outline several research challenges that, when resolved, will improve our understanding of the role of plant evolution in mediating the fire feedbacks driving Earth system processes. Understanding current patterns of fire and vegetation, as well as patterns of fire over geological time, requires research that incorporates evolutionary biology, ecology, biogeography, and the biogeosciences.
- Full Text:
- Date Issued: 2017
One size does not fit all: critical insights for effective community-based resource management in Melanesia
- Aswani, Shankar, Albert, Simon, Love, Mark
- Authors: Aswani, Shankar , Albert, Simon , Love, Mark
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145392 , vital:38434 , DOI: 10.1016/j.marpol.2017.03.041
- Description: In recent years, Fiji's approach of combining traditional systems of community-based coastal management and modern management systems has become a successful blueprint for marine conservation, particularly the Locally Managed Marine Area (LMMA) network model. As a result of this success, conservation practitioners have imported the Fiji LMMA model to the Solomon Islands and in Vanuatu in hope of replicating the purported success attained in Fiji. This paper argues that because tenure systems and associated political systems in Fiji, the Solomon Islands, and Vanuatu are substantially different, one cannot simply extrapolate the more centralized tenurial and political Fiji model to the decentralized tenurial and politically eclectic Solomons and Vanuatu. This paper provides an analysis of some of the various approaches used in these countries to make a case for why socio-political diversity and historical particulars matter to resource management and conservation-in-practice (and for any development interventions).
- Full Text:
- Date Issued: 2017
- Authors: Aswani, Shankar , Albert, Simon , Love, Mark
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145392 , vital:38434 , DOI: 10.1016/j.marpol.2017.03.041
- Description: In recent years, Fiji's approach of combining traditional systems of community-based coastal management and modern management systems has become a successful blueprint for marine conservation, particularly the Locally Managed Marine Area (LMMA) network model. As a result of this success, conservation practitioners have imported the Fiji LMMA model to the Solomon Islands and in Vanuatu in hope of replicating the purported success attained in Fiji. This paper argues that because tenure systems and associated political systems in Fiji, the Solomon Islands, and Vanuatu are substantially different, one cannot simply extrapolate the more centralized tenurial and political Fiji model to the decentralized tenurial and politically eclectic Solomons and Vanuatu. This paper provides an analysis of some of the various approaches used in these countries to make a case for why socio-political diversity and historical particulars matter to resource management and conservation-in-practice (and for any development interventions).
- Full Text:
- Date Issued: 2017
Environmental and social recovery asymmetries to large-scale disturbances in small island communities
- Aswani, Shankar, Van Putten, Ingrid, Miñarro, Sara
- Authors: Aswani, Shankar , Van Putten, Ingrid , Miñarro, Sara
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67325 , vital:29073 , https://doi.org/10.1007/s11069-016-2685-2
- Description: publisher version , People’s livelihoods in tropical small-island developing states are greatly dependent on marine ecosystem services. Yet services such as fisheries and coastal buffering are being degraded at an alarming rate, thus making people increasing vulnerable to protracted and sudden environmental changes. In the context of the occurrences of extreme events such as earthquakes and tsunamis, it is vital to uncover the processes that make people in these island states resilient, or not, to environmental disruptions. This paper compares people’s perceptions of social and environmental impacts after an extreme event in the Western Solomon Islands (11 different villages on 8 different islands) to better understand how knowledge systems influence the coupling of human and natural systems. We examine the factors that contributed to perceptions of respective recovery in the environmental versus the social domains across communities with different traditional governance and modernization characteristics in a tsunami impact gradient. First, we separately assessed, at the community and individual level, the potential determinants of perceived recovery in the environmental and social domains. At the community level, the average values of the perceived environmental and social recovery were calculated for each community (1 year after the tsunami), and at the individual level, normally distributed environmental and social recovery variables (based on the difference in perceptions immediately and 1 year after the tsunami) were used as dependent variables in two General Linear Models. Results suggest that environmental and social resilience are not always coupled correspondingly and, less unexpectedly, that asymmetries during recovery can occur as a result of the underlying social and ecological context and existing adaptive capacity. More generally, the study shows how by evaluating post-disturbance perceptional data in tsunami-affected communities, we can better understand how subjective perceptions of change can affect the (de)-coupling of human and natural systems.
- Full Text: false
- Date Issued: 2017
- Authors: Aswani, Shankar , Van Putten, Ingrid , Miñarro, Sara
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67325 , vital:29073 , https://doi.org/10.1007/s11069-016-2685-2
- Description: publisher version , People’s livelihoods in tropical small-island developing states are greatly dependent on marine ecosystem services. Yet services such as fisheries and coastal buffering are being degraded at an alarming rate, thus making people increasing vulnerable to protracted and sudden environmental changes. In the context of the occurrences of extreme events such as earthquakes and tsunamis, it is vital to uncover the processes that make people in these island states resilient, or not, to environmental disruptions. This paper compares people’s perceptions of social and environmental impacts after an extreme event in the Western Solomon Islands (11 different villages on 8 different islands) to better understand how knowledge systems influence the coupling of human and natural systems. We examine the factors that contributed to perceptions of respective recovery in the environmental versus the social domains across communities with different traditional governance and modernization characteristics in a tsunami impact gradient. First, we separately assessed, at the community and individual level, the potential determinants of perceived recovery in the environmental and social domains. At the community level, the average values of the perceived environmental and social recovery were calculated for each community (1 year after the tsunami), and at the individual level, normally distributed environmental and social recovery variables (based on the difference in perceptions immediately and 1 year after the tsunami) were used as dependent variables in two General Linear Models. Results suggest that environmental and social resilience are not always coupled correspondingly and, less unexpectedly, that asymmetries during recovery can occur as a result of the underlying social and ecological context and existing adaptive capacity. More generally, the study shows how by evaluating post-disturbance perceptional data in tsunami-affected communities, we can better understand how subjective perceptions of change can affect the (de)-coupling of human and natural systems.
- Full Text: false
- Date Issued: 2017
Customary management as TURFs: social challenges and opportunities
- Authors: Aswani, Shankar
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145403 , vital:38435 , DOI: 10.5343/bms.2015.1084
- Description: There is a growing interest in working with customary management (CM) systems to effectively manage benthic resources and small-scale fisheries. The underlying notion is that CM institution as territorial use rights in fisheries (TURFs) can be sufficiently adaptive and dynamic to create the local incentives that are necessary for promoting sustainable fishing practices and marine conservation more generally in a given region. This paper reviews the social opportunities and challenges of working with CM systems as a form of TURF, particularly in Oceania. A key conclusion is that policy makers and managers not only need to recognize natural interconnectivity in any one marine space, but also consider the social interconnectivity of stakeholders that covers customary TURFs. Only by recognizing and working with the existing social networks that overlay any given marine territory can the operational principles of CM (as reviewed in this paper) be effectively deployed for achieving some kind of bioeconomic efficiency and creating an equitable rights-based fisheries management system.
- Full Text:
- Date Issued: 2017
- Authors: Aswani, Shankar
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/145403 , vital:38435 , DOI: 10.5343/bms.2015.1084
- Description: There is a growing interest in working with customary management (CM) systems to effectively manage benthic resources and small-scale fisheries. The underlying notion is that CM institution as territorial use rights in fisheries (TURFs) can be sufficiently adaptive and dynamic to create the local incentives that are necessary for promoting sustainable fishing practices and marine conservation more generally in a given region. This paper reviews the social opportunities and challenges of working with CM systems as a form of TURF, particularly in Oceania. A key conclusion is that policy makers and managers not only need to recognize natural interconnectivity in any one marine space, but also consider the social interconnectivity of stakeholders that covers customary TURFs. Only by recognizing and working with the existing social networks that overlay any given marine territory can the operational principles of CM (as reviewed in this paper) be effectively deployed for achieving some kind of bioeconomic efficiency and creating an equitable rights-based fisheries management system.
- Full Text:
- Date Issued: 2017
Biosynthesis of silver nanoparticles from Acacia mearnsii De Wild stem bark and its antinociceptive properties
- Avoseh, Opeyemi N, Oyedeji, Opeoluwa O, Aremu, Olukayode, Nkeh-Chungag, Benedicta N, Songca, Sandile P, Oyedeji, Adebola Omowunmi, Mohan, Sneha, Oluwafemi, Oluwatobi S
- Authors: Avoseh, Opeyemi N , Oyedeji, Opeoluwa O , Aremu, Olukayode , Nkeh-Chungag, Benedicta N , Songca, Sandile P , Oyedeji, Adebola Omowunmi , Mohan, Sneha , Oluwafemi, Oluwatobi S
- Date: 2017
- Subjects: Metal nanoparticles , Acacia mearnsii , Nociceptive pain
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/1528 , vital:37774 , https://doi.org/10.1080/17518253.2017.1287310
- Description: The biosynthesis of silver nanoparticles (Ag-NPs) using the hydrosol extract of the dry stem bark of Acacia mearnsii as reducing and capping agents, and their antinociceptive properties are hereby reported. By varying the temperature and reaction time, the temporal evolution of the optical and morphological properties of the as-synthesized material was investigated. The NPs were characterized by UV–visible absorption spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS) and x-ray diffractometry (XRD) The optical analyses show that the position of the maximum surface plasmon resonance (SPR) peak is red-shifted as the reaction temperature decreased. The TEM micrographs show that the as-synthesized Ag-NPs are spherical while the X-ray diffraction shows that the material is highly crystalline with face-centered cubic structures. The anti-inflammatory efficacy, analyzed by the formalin model, indicates that the as-synthesized Ag-NPs are very effective, with an inhibition rate of about 76%.
- Full Text:
- Date Issued: 2017
- Authors: Avoseh, Opeyemi N , Oyedeji, Opeoluwa O , Aremu, Olukayode , Nkeh-Chungag, Benedicta N , Songca, Sandile P , Oyedeji, Adebola Omowunmi , Mohan, Sneha , Oluwafemi, Oluwatobi S
- Date: 2017
- Subjects: Metal nanoparticles , Acacia mearnsii , Nociceptive pain
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/1528 , vital:37774 , https://doi.org/10.1080/17518253.2017.1287310
- Description: The biosynthesis of silver nanoparticles (Ag-NPs) using the hydrosol extract of the dry stem bark of Acacia mearnsii as reducing and capping agents, and their antinociceptive properties are hereby reported. By varying the temperature and reaction time, the temporal evolution of the optical and morphological properties of the as-synthesized material was investigated. The NPs were characterized by UV–visible absorption spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDS) and x-ray diffractometry (XRD) The optical analyses show that the position of the maximum surface plasmon resonance (SPR) peak is red-shifted as the reaction temperature decreased. The TEM micrographs show that the as-synthesized Ag-NPs are spherical while the X-ray diffraction shows that the material is highly crystalline with face-centered cubic structures. The anti-inflammatory efficacy, analyzed by the formalin model, indicates that the as-synthesized Ag-NPs are very effective, with an inhibition rate of about 76%.
- Full Text:
- Date Issued: 2017
Between a cushion and a risky conversation: ARTS LOUNGE reviewed
- Authors: Baasch, Rachel M
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147703 , vital:38662 , https://doi.org/10.1080/00043389.2011.11877155
- Description: On the fringe of the National Arts Festival, at a point of transition between Rhodes University campus and the commercial side of Grahamstown, the walls of a former home and former horse-stable, now a research house, reverberate with the strain of cross-disciplinary, site-specific collaboration. The ARTS LOUNGE made its first official appearance at the Grahamstown National Arts Festival (ViPPA Research Center, Rhodes University) from 30 June to 9 July 2011. The ten-day event was organised by the Visual and Performing Arts of Africa Research (ViPPA) team in collaboration with musicians, artists, writers, performers and members of the public.
- Full Text:
- Date Issued: 2017
- Authors: Baasch, Rachel M
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147703 , vital:38662 , https://doi.org/10.1080/00043389.2011.11877155
- Description: On the fringe of the National Arts Festival, at a point of transition between Rhodes University campus and the commercial side of Grahamstown, the walls of a former home and former horse-stable, now a research house, reverberate with the strain of cross-disciplinary, site-specific collaboration. The ARTS LOUNGE made its first official appearance at the Grahamstown National Arts Festival (ViPPA Research Center, Rhodes University) from 30 June to 9 July 2011. The ten-day event was organised by the Visual and Performing Arts of Africa Research (ViPPA) team in collaboration with musicians, artists, writers, performers and members of the public.
- Full Text:
- Date Issued: 2017
Azide-derivatized gold nanosphere “clicked” to indium and zinc phthalocyanines for improved nonlinear optical limiting
- Bankole, Owolabi M, Nyokong, Tebello
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188249 , vital:44738 , xlink:href="https://doi.org/10.1016/j.molstruc.2017.01.088"
- Description: We report on the conjugation of azide-derivatized gold nanoparticles (AuNPs) to alkyne moieties of ZnPc and InPc via azide-alkyne Huisgen cycloaddition reaction to form phthalocyanines-AuNPs (MPc-AuNPs) conjugates. The detailed structural characterizations of the composites were in good agreement with the expected results. The nonlinear absorption coefficients and other nonlinear optical limiting parameters were almost two times larger for the conjugates compared to free phthalocyanines. We established direct relationship between improved photophysical characterizations and enhanced nonlinear effects of reverse saturable absorption mechanisms favoured by excited triplet absorption of the phthalocyanines in the presence of AuNPs. The combination of InPc with AuNPs resulted in the lowest limiting intensity value of 0.06 J/cm2, hence the best performance in terms of optical limiting.
- Full Text:
- Date Issued: 2017
- Authors: Bankole, Owolabi M , Nyokong, Tebello
- Date: 2017
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/188249 , vital:44738 , xlink:href="https://doi.org/10.1016/j.molstruc.2017.01.088"
- Description: We report on the conjugation of azide-derivatized gold nanoparticles (AuNPs) to alkyne moieties of ZnPc and InPc via azide-alkyne Huisgen cycloaddition reaction to form phthalocyanines-AuNPs (MPc-AuNPs) conjugates. The detailed structural characterizations of the composites were in good agreement with the expected results. The nonlinear absorption coefficients and other nonlinear optical limiting parameters were almost two times larger for the conjugates compared to free phthalocyanines. We established direct relationship between improved photophysical characterizations and enhanced nonlinear effects of reverse saturable absorption mechanisms favoured by excited triplet absorption of the phthalocyanines in the presence of AuNPs. The combination of InPc with AuNPs resulted in the lowest limiting intensity value of 0.06 J/cm2, hence the best performance in terms of optical limiting.
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- Date Issued: 2017