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Assessing climate risk to support urban forests in a changing climate

- Esperon-Rodriguez, Manuel, Rymer, Paul D, Power, Sally A, Barton, David N, Cariñanos, Paloma, Dobbs, Cynnamon, Eleuterio, Ana A, Escobedo, Francisco J, Hauer, Richard, Hermy, Martin, Jahani, Ali, Onyekwelu, Jonathan C, Östberg, Johan, Pataki, Diane, Randrup, Thomas B, Rasmussen, Tørres, Roman, Lara A, Russo, Alessio, Shackleton, Charlie M, Solfjeld, Ingjerd, Van Doorn, Natalie S, Wells, Matthew J, Wiström, Björn, Yan, Pengbo, Yang, Jun, Tjoelker, Mark G

Assessing the electrocatalytic activity of a localized push-pull system in cobalt phthalocyanine/graphene quantum dot hybrids

- Nkhahle, Reitumetse, Nyokong, Tebello

  • Authors: Nkhahle, Reitumetse , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/229909 , vital:49722 , xlink:href="https://doi.org/10.1016/j.matchemphys.2022.125842"
  • Description: In this study, two cobalt phthalocyanines (asymmetric complex 1) and symmetric (complex 2) were synthesized and conjugated to nitrogen-doped graphene quantum dots (NGQDs) through covalent and non-covalent means to create Co phthalocyanine (CoPc)-NGQDs hybrid systems. The CoPcs and conjugates were applied as electrode modifiers on a glassy carbon electrode in the electrochemical sensing of nitrite. Of the CoPcs alone, complex 1 performed better than complex 2 regarding the limits of detection (LoD) recorded (5.74 μM for 1 and 15.1 μM for 2). Regarding the conjugates/nanocomposites, the π-π stacked conjugate derived from complex 2 (2πNGQDs) demonstrated highly favourable electrochemical potential with an LoD value of 0.70 μM. The nanocomposites fashioned from complex 1 were marred by a reduced loading which rendered the conjugates poor electrochemical sensors. These observations however do not disqualify GQDs as complementary nanomaterials to phthalocyanines but rather shed light on seeking alternative routes to increasing the Pc loading in conjugates (more so in π-π stacked conjugates).
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  • Date Issued: 2022

Assessing the Impact of DNS Configuration on Low Bandwidth Networks

- Okuthe, J A, Terzoli, Alfredo

  • Authors: Okuthe, J A , Terzoli, Alfredo
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/430903 , vital:72726 , https://doi.org/10.1007/978-3-031-34896-9_6
  • Description: Domain name system (DNS) is an essential enabler for connecting us-ers and services on the Internet. DNS translates human readable do-main names into IP addresses and precedes client connection to a server via a domain name. DNS service is therefore expected to con-sume network bandwidth even though it offers no direct benefit to the user. Having observed the large component of DNS traffic on the com-munity network local loop in our previous study, we migrated the DNS service from a server on the LAN to the gateway router and reconfig-ured the cache time-to-live. Results from the analysis of network traffic captured from the gateway router interface show a 26% decrease in the downlink bandwidth utilization and 46% decline in the uplink bandwidth utilization. The DNS component of the local loop traffic reduces from 45.28% to 4.11%. On the other hand, the Web component of the local loop traffic increases from 49.42% to 95.49%. Data collected from a mirroring port on the LAN switch indicate a decrease in the DNS portion of the internal traffic from 0.38% to 0.18%. Although the DNS reconfigu-ration helps alleviate network bandwidth constraints and reduces DNS component of the traffic, the Web portion increases. The implementa-tion of effective, efficient and sustainable Web traffic management is therefore required.
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  • Date Issued: 2022

Asymmetrical zinc (II) phthalocyanines conjugated to metal tungstate nanoparticles for photoinactivation of Staphylococcus aureus

- Mgidlana, Sithi, Managa, Muthumuni, Nyokong, Tebello

  • Authors: Mgidlana, Sithi , Managa, Muthumuni , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/295718 , vital:57372 , xlink:href="https://doi.org/10.1080/00958972.2022.2090837"
  • Description: In this study, we report for the first time on the photodynamic antimicrobial chemotherapy (PACT) of asymmetrical zinc(II) phthalocyanines and their conjugates with nickel tungstate (NiWO4), cobalt tungstate (CoWO4) and bismuth tungstate (Bi2WO6) nanoparticles. CoWO4, NiWO4 and Bi2WO6 were capped with glutathione and covalently linked to three asymmetrical zinc(II) phthalocyanines for PACT. The plate count method was used to investigate the effect of covalently linking asymmetrical zinc(II) phthalocyanines to nanoparticles under light (for PACT against Staphylococcus aureus) and in the dark. Both Pc complexes and the conjugates indicated minimum dark-toxicity. The conjugates showed greater antimicrobial activity against a gram-positive and drug resistant bacteria, Staphylococcus aureus, than Pc complexes alone.
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  • Date Issued: 2022

Austral birds offer insightful complementary models in ecology and evolution

- Theuerkauf, Jörn, Villavicencio, Camilla P, Adreani, Nicholas M, Attisano, Alfredo, Craig, Adrian J F K, D’Amelio, Pietro B, Gula, Roman, Lee, Alan T K, Mentesana, Lucia, Quillfeldt, Petra, Quirici, Veronica, Quispe, René, Vásquez, Rodrigo A, Wingfield, John C, Masello, Juan F

  • Authors: Theuerkauf, Jörn , Villavicencio, Camilla P , Adreani, Nicholas M , Attisano, Alfredo , Craig, Adrian J F K , D’Amelio, Pietro B , Gula, Roman , Lee, Alan T K , Mentesana, Lucia , Quillfeldt, Petra , Quirici, Veronica , Quispe, René , Vásquez, Rodrigo A , Wingfield, John C , Masello, Juan F
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/449097 , vital:74788 , https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(22)00114-8
  • Description: The Southern Hemisphere differs from the Northern Hemisphere in many aspects. However, most ecological and evolutionary research is conducted in the Northern Hemisphere and its conclusions are extrapolated to the entire globe. Therefore, unique organismal and evolutionary characteristics of the south are overlooked. We use ornithology to show the importance of including a southern perspective. We present examples of plumage pigmentation, brood-parasitic nestling ejection, flightlessness, female song, and female aggression modulated by progesterone as complementary models for investigating fundamental biological questions. More research in the Southern Hemisphere, together with increased cooperation among researchers across the hemispheres and within the Southern Hemisphere, will provide a greater global outlook into ecology and evolution.
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  • Date Issued: 2022

Best of both worlds: The thermal physiology of Hydrellia egeriae, a biological control agent for the submerged aquatic weed, Egeria densa in South Africa

- Smith, Rosali, Coetzee, Julie A, Hill, Martin P

  • Authors: Smith, Rosali , Coetzee, Julie A , Hill, Martin P
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/417913 , vital:71494 , xlink:href="https://doi.org/10.1007/s10526-022-10142-w"
  • Description: The submerged aquatic weed, Egeria densa Planch. (Hydrocharitaceae) or Brazilian waterweed, is a secondary invader of eutrophic freshwater systems in South Africa, following the successful management of floating aquatic weeds. In 2018, the leaf and stem-mining fly, Hydrellia egeriae Rodrigues-Júnior, Mathis and Hauser (Diptera: Ephydridae), was released against E. densa, the first agent released against a submerged aquatic weed in South Africa. During its life stages, the biological control agent is exposed to two environments, air and water. The thermal physiology of both life stages was investigated to optimize agent establishment through fine-tuned release strategies. The thermal physiological limits of H. egeriae encompassed its host plant’s optimal temperature range of 10 to 35 °C, with lower and upper critical temperatures of 2.6 to 47.0 °C, lower and upper lethal temperatures of − 5.6 and 40.6 °C for adults, and − 6.3 to 41.3 °C for larvae. Results from development time experiments and degree-day accumulation showed that the agent is capable of establishing at all E. densa sites in South Africa, with between 6.9 and 8.3 generations per year. However, cold temperatures (14 °C) prolonged the agent’s development time to three months, allowing it to only develop through one generation in winter. Predictions obtained from laboratory thermal physiology experiments corroborates field data, where the agent has established at all the sites it was released.
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  • Date Issued: 2022

Beyond epistemology: the challenge of reconceptualising knowledge in higher education

- Luckett, Kathy, Blackie, Margaret A L

  • Authors: Luckett, Kathy , Blackie, Margaret A L
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426598 , vital:72371 , xlink:href="https://doi.org/10.1080/13562517.2022.2111206"
  • Description: In this Point of Departure, we build on the scholarship of Suellen Shay. Shay explored the nature of higher education, examining assessment and the relation between curriculum and knowledge structures across several disciplines. She drew on the work of Bernstein and in her later work responded to the calls for decolonisation. We first contextualise the work of Basil Bernstein and explain its attraction for scholars of education development in the South African HE context. We then provide a brief summary of recent decolonial scholarship. On this basis, we speculate what a critique and caricature of the Bernsteinian tradition by the decolonial school might look like. In turn we offer a caricatured rebuttal by the Bernsteinian school to the decolonial critique. Finally, we pull our argument together and, by drawing on Bhaskar’s critical realism, assert the importance of an adequate theorisation of ontology.
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  • Date Issued: 2022

Can Local Knowledge of Small-Scale Fishers Be Used to Monitor and Assess Changes in Marine Ecosystems in a European Context?

- Piñeiro-Corbeira, Cristina, Barrientos, Sara, Barreiro, Rodolfo, Aswani, Shankar, Pascual-Fernández, José, De la Cruz-Modino, Raquel

  • Authors: Piñeiro-Corbeira, Cristina , Barrientos, Sara , Barreiro, Rodolfo , Aswani, Shankar , Pascual-Fernández, José , De la Cruz-Modino, Raquel
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/391331 , vital:68642 , ISBN 978-3-031-01980-7 , https://doi.org/10.1007/978-3-031-01980-7_24
  • Description: Significance Statement In the last decades, many coastal areas have observed dramatic changes in marine ecosystems, due to anthropogenic and environmental alterations. The general absence of long-term data sets in the marine environment and, more specifically, on benthic and demersal communities represents a severe issue for management and conservation. We propose to incorporate the small-scale fishers’ knowledge and science for better policy recommendations, both in terms of fisheries optimization and resource conservation. Based on two different cases of study with diverse ecosystems, we explore the combination of quantitative and qualitative tools, and participative techniques used to incorporate fishers’ local ecological knowledge. The results highlight fishers’ capacity to identify coastal and marine landscapes resources and changes, reinforcing and complementing the scientific assessment.
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  • Date Issued: 2022

Caves, crevices and cooling capacity roost microclimate predicts heat tolerance in bats

- Czenze, Zenon J, Smit, Ben, van Jaarsveld, Barry, Freeman, Marc T, McKechnie, Andrew

  • Authors: Czenze, Zenon J , Smit, Ben , van Jaarsveld, Barry , Freeman, Marc T , McKechnie, Andrew
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/441571 , vital:73899 , https://doi.org/10.1111/1365-2435.13918
  • Description: The microsites that animals occupy during the rest phase of their circa-dian activity cycle influence their physiology and behaviour, but relative-ly few studies have examined correlations between interspecific varia-tion in thermal physiology and roost microclimate. Among bats, there is some evidence that species exposed to high roost temperatures (Troost) possess greater heat tolerance and evaporative cooling capacity, but the small number of species for which both thermal physiology and roost microclimate data exist mean that the generality of this pattern remains unclear.
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  • Date Issued: 2022

Challenges of implementing management accounting innovations

- Oyewo, Babajide, Hussain, Syed T, Simbi, Chipo

  • Authors: Oyewo, Babajide , Hussain, Syed T , Simbi, Chipo
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426264 , vital:72336 , xlink:href="https://www.jstor.org/stable/48717780"
  • Description: This study investigates the challenges of implementing innovative management accounting techniques, referred to as strategic management accounting (SMA), the interrelationship among the challenges and the impact of the challenges on SMA usage intensity. From the analysis of survey data obtained from listed manufacturing companies in Nigeria, the result supports the conclusion that SMA implementation challenges are interrelated. However, lack of top management support and low awareness/lack of knowledge are contributory to most of the implementation challenges. The challenges discouraging the intensive use of SMA are the perception that SMA implementation is unnecessary as strategy issues are already integrated in other functions within the organization, high implementation cost and problems relating to information flow between departments within the organization. The current study contributes to knowledge in the sense that it is the first (to the researchers’ knowledge) to examine specifically the interrelationship among SMA implementation challenges in the Nigerian context, thereby drawing attention to the need to consider the challenges to embracing management accounting innovations holistically. Knowledge of SMA implementation challenges could help explain the low adoption rate of SMA in developing countries. Such knowledge might be helpful in providing a robust response to the challenges of implementing management accounting innovations.
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  • Date Issued: 2022

Characterising the shared genetic influences between schizophrenia and subcortical brain regions

- Wooton, Olivia, Campbell, Megan M, Jahanshad, Neda, Thompson, Paul, Stein, Dan J, Dalvie, Shareefa

  • Authors: Wooton, Olivia , Campbell, Megan M , Jahanshad, Neda , Thompson, Paul , Stein, Dan J , Dalvie, Shareefa
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/302450 , vital:58197 , xlink:href="https://doi.org/10.1016/j.euroneuro.2022.07.533"
  • Description: Background: Abnormalities in brain structural volumes are well established in schizophrenia (SZ) and have been proposed as an endophenotype for the disorder. Despite increasing interest in the genetic relationship between brain structural volumes and SZ, our knowledge of the genetic overlap between the phenotypes is limited. This study aims to extend our current understanding of the shared genetic influences between SZ and subcortical brain volumes using data from the latest genome-wide association studies for the respective phenotypes (GWAS) and novel statistical approaches. Additionally, we will explore whether the association between schizophrenia and abnormal regional brain volumes is causal in nature. Methods: Summary statistics were obtained from the largest Psychiatric Genomic Consortium (PGC)-SZ GWAS (Ncase = 69,369, Ncontrol = 236,642) and the CHARGEENIGMA-UKBB GWAS of volumetric measures for eight subcortical brain regions (the nucleus accumbens, amygdala, brainstem, caudate nucleus, hippocampus, globus pallidus, putamen, and thalamus), and total intracranial volume (N = 30,983 - 40,380). Single nucleotide polymorphism (SNP) effect concordance analysis (SECA) was used to assess pleiotropy and concordance. Genetic correlation was assessed using linkage disequilibrium score regression (LDSR) and the pleiotropy informed conditional FDR approach was applied to identify SNPs associated with SZ conditional on their association with subcortical brain volumes. Mendelian randomization (MR) was used to test for causal association between SZ and each brain region. Results: There was evidence of global pleiotropy between SZ, and all examined subcortical brain regions. Inverse concordance between the genetic determinants of SZ and volumes of the nucleus accumbens, amygdala, brainstem, hippocampus, and thalamus was observed. Increased statistical power to detect SZ risk loci was shown when conditioning on subcortical brain volumes. There was no significant evidence for a causal effect of any of the examined brain regions on schizophrenia risk. Discussion: These data confirm the shared genetic basis of SZ and specific intracranial and subcortical brain volumes and provide evidence for negative concordance between SZ and volumes of the nucleus accumbens, amygdala, brainstem, hippocampus, and thalamus. Leveraging the genetic overlap between SZ and subcortical brain volumes has the potential to provide novel insights into the biological basis of the disorder.
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  • Date Issued: 2022

Climatic suitability and compatibility of the invasive Iris pseudacorus L.(Iridaceae) in the Southern Hemisphere: Considerations for biocontrol

- Minuti, Gianmarco, Stiers, Iris, Coetzee, Julie A

  • Authors: Minuti, Gianmarco , Stiers, Iris , Coetzee, Julie A
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/423293 , vital:72045 , xlink:href="https://doi.org/10.1016/j.biocontrol.2022.104886"
  • Description: Iris pseudacorus L. (Iridaceae) is an emergent macrophyte native to Europe, North Africa and western Asia. Considered invasive in wetland habitats around the world, this species is now the target of a biocontrol programme in the Southern Hemisphere. Native range surveys of the weed led to the selection of the flea beetle, Aphthona nonstriata Goeze (Coleoptera: Chrysomelidae), as a candidate biocontrol agent. An important aspect to consider in weed biocontrol is the ability of an agent to establish and thrive in the environment where it is released. Climatic incompatibility between source and intended release sites can in fact limit the success of a biocontrol programme. In the current study, the potential climatic niche of I. pseudacorus and A. nonstriata in the Southern Hemisphere was analysed. The ecological niche modelling software MaxEnt was used to map the climatic suitability of both organisms across invaded regions in South America, southern Africa and Australasia. Furthermore, occurrence records from each invaded range were used independently to model the climatic compatibility of I. pseudacorus in Europe, in order to prioritize areas of the native range to explore during future surveys for potential biocontrol agents. The models identified areas at high risk of invasion by I. pseudacorus in northern Argentina, Uruguay, southern Brazil and central Chile, as well as numerous provinces of eastern South Africa, Lesotho, southern Australia and New Zealand. Accordingly, the highest climatic suitability for A. nonstriata was predicted across the humid temperate climates of north-east Argentina, Uruguay, southern Brazil, southern South Africa, south-east Australia and New Zealand. These results can eventually be used in future release plans to prioritize areas where establishment and survival of the agent is expected to be highest. At the same time, it may be useful to search the native range of the weed for biological control agents showing high climatic adaptation towards the intended release sites of each invaded range. In this regards, our climatic compatibility models identified high-priority areas across the Mediterranean regions of Italy and southern France, as well as the temperate regions of central and western Europe. Altogether, the current study provides useful new information to tackle the invasion and advance the biocontrol programme of I. pseudacorus in the Southern Hemisphere.
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  • Date Issued: 2022

Comparative avifaunal richness and diversity in invasive Acacia dealbata patches and adjacent montane grasslands

- Seath, Jessica, Shackleton, Charlie M

  • Authors: Seath, Jessica , Shackleton, Charlie M
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/406585 , vital:70287 , xlink:href="https://hdl.handle.net/10520/ejc-afzoo_v57_i1_a12"
  • Description: Abstract Invasive alien species are regarded as the second greatest threat to biodiversity globally. Yet, at a local scale their effects may vary, underlying the requirement for more local-scale studies across taxa and settings. Here we consider the effects of an alien invasive tree (Acacia dealbata, 5–8 m tall) on avifaunal numbers, richness and diversity in A. dealbata patches of three sizes relative to adjacent montane grasslands. Analysis of historical aerial photographs showed that A. dealbata first occurred in the area in the late 1930s/early 1940s and has continued to spread, despite some efforts by the landowner to keep it in check. It now covers approximately 11% of the site. This has provided habitat for a number of bird species more characteristic of wooded vegetation types. The number, richness and diversity of birds were greater in A. dealbata patches than the adjacent grasslands of equivalent size. These measures increased with increasing patch size, but more rapidly for A. dealbata patches than grassland ones. Only six of the 48 species of birds recorded were common between the two vegetation types. The most common feeding guild in the A. dealbata patches was insectivores, whereas in the grasslands it was omnivores. Although the invasion of A. dealbata has added to the habitat diversity of the area, thereby facilitating increased avifaunal diversity, if it continues to spread, then the populations and perhaps richness of grassland birds are likely to be negatively affected.
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  • Date Issued: 2022

Conceptualising public-private partnerships for social innovation through community engagement in higher education institutions

- Sibhensana, Bertha, Maistry, Savathrie M

  • Authors: Sibhensana, Bertha , Maistry, Savathrie M
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/426269 , vital:72337 , xlink:href="https://hdl.handle.net/10520/ejc-high_v37_n1_a11"
  • Description: The achievement of human social and economic development has been equated to social innovation. Innovation that focuses on the marginalised communities in South Africa becomes necessary to redress the inequalities created pre-democracy. As social institutions, higher education institutions are well positioned to deal with the challenges of the 21st century, which include poverty, unemployment and inequality, through promoting social innovation. In democratic South Africa the relationship between an institution of higher learning and the community can be viewed as a social innovation. This submission implies that one of the objectives of community engagement as a core function of universities, is to drive the social innovation agenda. The university’s contributions to community development can be viewed in terms of its ability to commit to social innovation. It is a better vehicle for understanding and creating social value in all its forms.
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  • Date Issued: 2022

Constellations, technicality, iconisation and Eskom: A case from South Africa’s Business Day

- Siebörger, Ian, Adendorff, Ralph D

  • Authors: Siebörger, Ian , Adendorff, Ralph D
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/385350 , vital:68010 , xlink:href="https://doi.org/10.2989/16073614.2022.2040369"
  • Description: This article uses Legitimation Code Theory (LCT) and systemic functional linguistics (SFL) to explore interactions between various resources for building economic and political knowledge in a 2015 article from Business Day, a South African newspaper, concerning the country’s energy crisis. We use LCT to observe how three constellations are built in the article: a ‘developmental state’ constellation; a ‘neo-liberal’ constellation; and another underarticulated constellation that selectively draws ideas from both the preceding constellations. These constellations are built through the unfolding of the text using various linguistic resources, which we describe using SFL, including technicality and iconisation. We identify instances where words are charged with both ideational and axiological meaning concurrently, challenging existing understandings of the process of iconisation.
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  • Date Issued: 2022

Cross boundary fluxes: Basal resource use by aquatic invertebrates matches fatty acid transfers from river to land

- Moyo, Sydney, Richoux, Nicole B

  • Authors: Moyo, Sydney , Richoux, Nicole B
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/454304 , vital:75334 , xlink:href="https://doi.org/10.1016/j.limno.2022.126035"
  • Description: Emerging insects transfer valuable lipids originating in aquatic food sources to terrestrial consumers. The objective of this study was to determine how the export of physiologically important fatty acids from a river to adjacent land via insect emergence relates to the type and quality of the aquatic food consumed, and which emerging insects were primarily responsible for these fluxes. We ran mixing models and hypervolumes incorporating stable carbon isotope ratios of basal resources and emergent invertebrates to determine the major contributors to insect larvae diets. Our data revealed that aquatic food sources (epiphyton, epilithon and suspended particulate matter) were the major organic matter sources (more than 50 %) supporting consumers (Diptera, Ephemeroptera, Odonata and Trichoptera), with allochthonous food sources (C3 plants) being of importance at upstream sites. We calculated fluxes of highly unsaturated fatty acids (HUFAs) via emerging insects and found that these corresponded with the spatial and temporal patterns in the nutritional quality of these same basal resources in the river (quality measured as concentrations of HUFAs). These patterns provide evidence of a direct coupling between food quality and trophic subsidy fluxes from water to land, particularly by emergent dipterans and ephemeropterans.
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  • Date Issued: 2022

Cultural Seascapes in the ‘Sea of Calms’ and La Restinga Coast

- De la Cruz-Modino, Raquel, Piñeiro-Corbeira, Cristina, Aswani, Shankar, González-Cruz, Carla, Domínguez, David, Ordóñez García, Paula, Santana-Talavera, Agustín, Pascual-Fernández, José

  • Authors: De la Cruz-Modino, Raquel , Piñeiro-Corbeira, Cristina , Aswani, Shankar , González-Cruz, Carla , Domínguez, David , Ordóñez García, Paula , Santana-Talavera, Agustín , Pascual-Fernández, José
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/391319 , vital:68641 , ISBN 978-3-031-07289-5 , https://doi.org/10.1007/978-3-031-07289-5
  • Description: El Hierro has been characterized by the balance between human development and environmental sustainability. The island was historically far from the mass tourism developments dominant on the other Canary Islands. Tourism accommodations in El Hierro are few compared to more developed coastal areas in the Archipelago, and recreational activities are mainly linked to cultural and natural sites and resources. This chapter focuses on La Restinga fishing village and its coasts, where the ‘Sea of Calms’ and one multiple-use Marine Reserve (MR) are located, both of which became popular over the last decade. The tourist development experience has promoted a new way of looking at the sea and conceptualizing its habitats and populations. In 2014, after the submarine volcano eruption occurred in 2011, we estimated that at least 25,391 dives had been carried out in the diving spots established by the MR and other diving sites close to La Restinga. Despite the difficulties experienced after the volcano eruption, a unique imaginaire has been consolidated, thanks to the image of the island's exclusive nature and iconic elements. In addition, the rapid recovery of the destination is an excellent example of how the tourism system can adapt and incorporate unexpected events such as volcanic eruptions.
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  • Date Issued: 2022

Decoration of glass wool with zinc (II) phthalocyanine for the photocatalytic transformation of methyl orange

- Sindelo, Azole, Britton, Jonathan, Lanterna, Anabel E, Scaiano, Juan C, Nyokong, Tebello

  • Authors: Sindelo, Azole , Britton, Jonathan , Lanterna, Anabel E , Scaiano, Juan C , Nyokong, Tebello
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/295742 , vital:57374 , xlink:href="https://doi.org/10.1016/j.jphotochem.2022.114127"
  • Description: Zinc phthalocyanines containing one (mono carboxy phenoxy, ZnMCPPc), four (tetra carboxy phenoxy, ZnTCPPc), and eight (tetra isophthalic acid, ZnTIPAPc) carboxyl groups were covalently conjugated to amine-functionalized glass wool (GW). The GW-Pcs were characterized and evaluated for singlet oxygen generation. The photocatalytic efficiencies of the GW-Pcs were assessed using methyl orange. Glass wool alone and the modified conjugates exhibited low to no degradation of methyl orange in the dark. The improved catalytic rate was observed for GW-ZnMCPPc and GW-ZnTCPPc compared to GW-ZnTIPAPc due to the latter's lower singlet oxygen quantum yield generation. In addition, the modified glass wool was recyclable, making it suitable candidates for future environmental applications.
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  • Date Issued: 2022

Deep face-iris recognition using robust image segmentation and hyperparameter tuning

- Brown, Dane L

  • Authors: Brown, Dane L
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/465145 , vital:76577 , xlink:href="https://link.springer.com/chapter/10.1007/978-981-16-3728-5_19"
  • Description: Biometrics are increasingly being used for tasks that involve sensitive or financial data. Hitherto, security on devices such as smartphones has not been a priority. Furthermore, users tend to ignore the security features in favour of more rapid access to the device. A bimodal system is proposed that enhances security by utilizing face and iris biometrics from a single image. The motivation behind this is the ability to acquire both biometrics simultaneously in one shot. The system’s biometric components: face, iris(es) and their fusion are evaluated. They are also compared to related studies. The best results were yielded by a proposed lightweight Convolutional Neural Network architecture, outperforming tuned VGG-16, Xception, SVM and the related works. The system shows advancements to ‘at-a-distance’ biometric recognition for limited and high computational capacity computing devices. All deep learning algorithms are provided with augmented data, included in the tuning process, enabling additional accuracy gains. Highlights include near-perfect fivefold cross-validation accuracy on the IITD-Iris dataset when performing identification. Verification tests were carried out on the challenging CASIA-Iris-Distance dataset and performed well on few training samples. The proposed system is practical for small or large amounts of training data and shows great promise for at-a-distance recognition and biometric fusion.
  • Full Text:
  • Date Issued: 2022

Deep Learning Approach to Image Deblurring and Image Super-Resolution using DeblurGAN and SRGAN

- Kuhlane, Luxolo L, Brown, Dane L, Connan, James, Boby, Alden, Marais, Marc

  • Authors: Kuhlane, Luxolo L , Brown, Dane L , Connan, James , Boby, Alden , Marais, Marc
  • Date: 2022
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/465157 , vital:76578 , xlink:href="https://www.researchgate.net/profile/Luxolo-Kuhlane/publication/363257796_Deep_Learning_Approach_to_Image_Deblurring_and_Image_Super-Resolution_using_DeblurGAN_and_SRGAN/links/6313b5a01ddd44702131b3df/Deep-Learning-Approach-to-Image-Deblurring-and-Image-Super-Resolution-using-DeblurGAN-and-SRGAN.pdf"
  • Description: Deblurring is the task of restoring a blurred image to a sharp one, retrieving the information lost due to the blur of an image. Image deblurring and super-resolution, as representative image restoration problems, have been studied for a decade. Due to their wide range of applications, numerous techniques have been proposed to tackle these problems, inspiring innovations for better performance. Deep learning has become a robust framework for many image processing tasks, including restoration. In particular, generative adversarial networks (GANs), proposed by [1], have demonstrated remarkable performances in generating plausible images. However, training GANs for image restoration is a non-trivial task. This research investigates optimization schemes for GANs that improve image quality by providing meaningful training objective functions. In this paper we use a DeblurGAN and Super-Resolution Generative Adversarial Network (SRGAN) on the chosen dataset.
  • Full Text:
  • Date Issued: 2022
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