Showing items 261 - 280 of 667

Your selections:

Genetic analysis reveals harvested Lethrinus nebulosus in the Southwest Indian Ocean comprise two cryptic species

  • Authors: Healey, Amy J E , Gouws, Gavin , Fennessy, Sean T , Kuguru, Baraka , Sauer, Warwick H H , Shaw, Paul W , McKeown, Niall J
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/124538 , vital:35626 , https://doi.10.1093/icesjms/fsx245
  • Description: This study initially aimed to investigate the genetic population/stock structuring of Lethrinus nebulosus in the Southwest Indian Ocean (SWIO) to inform management practices in light of emerging evidence of overharvesting of this species throughout its distribution. Adult samples were genotyped for 14 nuclear microsatellites and by sequencing fragments of the mtDNA control region and COI gene. A salient feature of the data was the congruent cyto-nuclear partitioning of samples into two high divergent, reciprocally monophyletic groups. This indicates that despite no a priori evidence, hitherto described L. nebulosus in the SWIO comprises two cryptic species that co-occur among southern samples. This intermingling indicates that, at least in southern samples, both species are being indiscriminately harvested, which may severely compromise sustainability. Limited microsatellite differentiation was detected within both species, though there was some evidence of isolation in the Mauritian population. In contrast, mtDNA revealed a pattern consistent with chaotic genetic patchiness, likely promoted by stochastic recruitment, which may necessitate a spatial bet-hedging approach to management to satisfy fishery management and conservation goals.
  • Full Text:

Genomic analysis reveals multiple mismatches between biological and management units in yellowfin tuna (Thunnus albacares)

  • Authors: Mullins, Rachel B , McKeown, Niall J , Sauer, Warwick H H , Shaw, Paul W
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/124549 , vital:35627 , https://doi.10.1093/icesjms/fsy102
  • Description: The South African (SAF) yellowfin tuna (Thunnus albacares) fishery represents a potential example of misalignment between management units and biological processes. The SAF fishery spans an operational stock with a boundary at 20_E, either side of which fish are considered part of Atlantic or Indian Ocean regional stocks. However, the actual recruitment of fish from Atlantic and Indian Ocean spawning populations into SAF waters is unknown. To address this knowledge gap, genomic analysis (11 101 SNPs) was performed on samples from Atlantic and Indian Ocean spawning sites, including SAF sites spanning the current stock boundary. Outlier loci conferred high discriminatory power to assignment tests and revealed that all SAF fish were assigned to the Indian Ocean population and that no Atlantic Ocean fish appeared in the SAF samples. Additionally, several Indian Ocean migrants were detected at the Atlantic spawning site demonstrating asymmetric dispersal and the occurrence of a mixed-stock fishery in Atlantic waters. This study highlights both the spatial inaccuracy of current stock designations and a misunderstanding of interactions between the underlying biological units, which must be addressed in light of local and global declines of the species. Specifically, the entire SAF fishery must be managed as part of the Indian Ocean stock.
  • Full Text:

Geometry of deformed special relativity

  • Authors: Sixaba, Vuyile
  • Date: 2018
  • Subjects: Special relativity (Physics) , Quantum gravity , Quantum theory , Geometry , Heisenberg uncertainty principle
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/59478 , vital:27615
  • Description: We undertake a study of the classical regime in which Planck's constant and Newton's gravitational constant are negligible, but not their ratio, the Planck mass, in hopes that this could possibly lead to testable quantum gravity (QG) effects in a classical regime. In this quest for QG phenomenology we consider modifications of the standard dispersion relation of a free particle known as deformed special relativity (DSR). We try to geometrize DSR to find the geometric origin of the spacetime and momentum space. In particular, we adopt the framework of Hamilton geometry which is set up on phase space, as the cotangent bundle of configuration space in order to derive a purely phase space formulation of DSR. This is necessary when one wants to understand potential links of DSR with modifications of quantum mechanics such as Generalised Uncertainty Principles. It is subsequently observed that space-time and momentum space emerge naturally as curved and intertwined spaces. In conclusion we mention examples and applications of this framework as well as potential future developments.
  • Full Text:

Global trends of local ecological knowledge and future implications

  • Authors: Aswani, Shankar , Lemahieu, Anne , Sauer, Warwick H H
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/70504 , vital:29668 , https://doi.org/10.1371/journal.pone.0195440
  • Description: Local and indigenous knowledge is being transformed globally, particularly being eroded when pertaining to ecology. In many parts of the world, rural and indigenous communities are facing tremendous cultural, economic and environmental changes, which contribute to weaken their local knowledge base. In the face of profound and ongoing environmental changes, both cultural and biological diversity are likely to be severely impacted as well as local resilience capacities from this loss. In this global literature review, we analyse the drivers of various types of local and indigenous ecological knowledge transformation and assess the directionality of the reported change. Results of this analysis show a global impoverishment of local and indigenous knowledge with 77% of papers reporting the loss of knowledge driven by globalization, modernization, and market integration. The recording of this loss, however, is not symmetrical, with losses being recorded more strongly in medicinal and ethnobotanical knowledge. Persistence of knowledge (15% of the studies) occurred in studies where traditional practices were being maintained consiously and where hybrid knowledge was being produced as a resut of certain types of incentives created by economic development. This review provides some insights into local and indigenous ecological knowledge change, its causes and implications, and recommends venues for the development of replicable and comparative research. The larger implication of these results is that because of the interconnection between cultural and biological diversity, the loss of local and indigenous knowledge is likely to critically threaten effective conservation of biodiversity, particularly in community-based conservation local efforts.
  • Full Text:

Glycosylated zinc phthalocyanine-gold nanoparticle conjugates for photodynamic therapy

  • Authors: Dube, Edith , Oluwole, David O , Nwaji, Njemuwa , Nyokong, Tebello
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/234524 , vital:50205 , xlink:href="https://doi.org/10.1016/j.saa.2018.05.081"
  • Description: In this work, we report on the synthesis of tris-[(2,2,7,7-tetramethyltetrahydro-3aH-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methoxy)-2-(4-benzo[d]thiazol-2-ylphenoxyphthalocyaninato] zinc(II) (complex 3) and its linkage to gold nanoparticles (AuNPs) of different shapes through S-Au/N-Au self-assembly. The conjugates of complex 3 (with both gold nanorods (AuNR) and nanospheres (AuNS)), displayed decreased fluorescence quantum yield with corresponding improved triplet and singlet quantum yields compared to complex 3 alone, however 3-AuNR showed improved properties than 3-AuNS. Complex 3 showed relatively low in vitro dark cytotoxicity against the epithelial breast cancer cells with cell survival ≥ 85% at concentration ≤ 160 μg/mL but afforded reduced photodynamic therapy activity which may be due to aggregation. 3-AuNR afforded superior PDT activity with more than 50% viable cells at concentration ≥ 40 μg/mL in comparison to 3-AuNS with more than 50% viable cells at concentration ≥ 80 μg/mL. The superior activity of 3-AuNR is attributed to the photothermal therapy effect since nanorods absorb more light at 680 nm than nanospheres.
  • Full Text:

Going to university: the Influence of higher education on the lives of young South Africans

Graphene quantum dots and their metallophthalocyanines nanoconjugates as novel photoluminescent nanosensors

  • Authors: Achadu, Ojodomo John
  • Date: 2018
  • Subjects: Quantum dots , Graphene , Phthalocyanines , Nanoconjugates , Novel photoluminescent nanosensors , Metallophthalocyanines
  • Language: English
  • Type: text , Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10962/60719 , vital:27821
  • Description: The fabrication and application of graphene quantum dots (GQDs)-based photoluminescent probes for the detection of analytes is presented. GQDs were functionalized with complexes such as metallophthalocyanines (MPcs), metal nanoparticles (Au@Ag NPs), 2,2,6,6-tetramethyl(piperidin-1-yl)oxyl (TEMPO), maleimide and thymine for the sensing of target analytes such as ascorbic acid (AA), biothiols (cysteine, homocysteine and glutathione) and mercury ion (Hg²+). The design strategy and approach was based on the quenching of the fluorescence of the GQDs upon functionalization with the above-mentioned complexes, which could be restored in the presence of the target analytes (due to their specific interaction affinity with the complexes). For the detection of AA, GQDs were covalently and/or non-covalently conjugated to TEMPO-bearing complexes to form GQDs-4A-TEMPO and GQDs-TEMPO-MPc systems with nanomolar limits of detection. For the detection of biothiols, Au@Ag NPs and maleimide-bearing complexes (MPc), which have specific affinity to interact with biothiols, were deployed. Hg²+ detection involved the use of GQDs and/or MPcs with thiol and thymine groups, respectively. In addition, a smart sensing platform was designed for the dual detection of biothiols and Hg²+ using supramolecular hybrid of polyethyleneimine functionalized-GQDs and MPc-Au@Ag conjugate. The probe could detect, in a sequential manner, Hg²+ and biothiols with high sensitivity. Results obtained from the LODs of the probes showed that GQDs sensing performances could be enhanced in the presence of MPcs. The probes designed in this work were successfully deployed in the assays of the target analytes in real samples and the recoveries obtained confirmed the analytical applicability of the probes.
  • Full Text:

Graphite: origin, deposits and economics : an exploration study of the Orom Graphite project

  • Authors: Van den Berg, Jacobus Petrus
  • Date: 2018
  • Subjects: Graphite , Ore deposits , Geophysics , Graphite mines and mining Economic aspects Africa, East , Trenches , Project management
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/63786 , vital:28489
  • Description: Developing exploration projects successfully requires that the Reasonable Prospects for Eventual Economic Extraction (RPEEE) be confirmed and based on the global market perception and trend. The exploration methods applied in the attempt to establish this RPEEE must be based on a key management framework that assures the results, and eventually the conclusion, are obtained with best practical and technical approaches whilst managing the risks and capitalizing on each result. The Orom Graphite project is located within the East African Orogenic belt, a suture zone between the Congo craton and the SLAMIN shield, formed during the formation of Gondwana during the late Proterozoic to early-Phanerozoic era. The closing of the Mozambique ocean, and the eventual collision between the craton and shield, occurred along the paleo-earths equator and migrated towards lower latitudes. This, along with the period’s biodiversity boom, provided the perfect deposition environment for carbonaceous sediments which were later metamorphosed to amphibolite and granulites grade metamorphism, resulting in the carbonization and the eventual graphitization of these carbonaceous sediments. The project is located within a poorly developed part of Uganda with the closest port situated some 1 500 km to the east in Kenya. The poorly developed infrastructure along with probable high logistical cost assigns a low competitivity index if compared to the economic costs of peer projects. However, the potential resources of the Orom Graphite project suggest that the Life of Mine (LOM) can rival the largest resource currently reported within the market. The current market conditions suggest that a possible oversupply of graphite concentrate will dominate the market within the next 4 to 10 years. This suggests that new graphite projects such as the Orom Graphite project are likely to develop into the production phase once the global supply and demand stabilize. This requires the Orom Graphite project to develop from its current scoping study level to a project development study level associated with a definitive feasibility study. To date, the project developed through mapping, reconnaissance drilling, geophysical survey and trenching programs increasing the Net Present Value (NPV) considerably based upon a Cost-Based Valuation approach using Prospectivity Enhancement Multiplier (PEM). The metallurgical studies could however not produce a graphite concentrate product within industrial grade standards. The risk associated with developing the project further into the Mineral Resource Estimation (MRE) phase was quantified and risk was evaluated by implementing a point decision tree and calculating the Expected Monetary Value (EMV). Due to the unfavourable metallurgical results obtained to date, the risk associated with undertaking an additional metallurgical test is considerable with a slight chance of producing a negative project value estimated at 65%. JP van den Berg Rhodes University Overall, the Orom Graphite project contains favourable geological formations with a potential large resource. Market trends indicate that a considerable resource is currently being developed and can supply the global market for the next 4 to 10 years. The project’s location within a landlocked country decreases its economic competitiveness with peer project and the unfavourable, but not conclusive, metallurgical results obtained during the scoping phase do not instil confidence that the project will develop into a productive mine soon. Managing the project development with future graphite demand in mind is the key to determining whether the project still has future value.
  • Full Text:

Green skills Transformative niches for greening work

  • Authors: Ramsarup, Preesha , Rosenberg, Eureta , Lotz-Sisitka, Heila , Jenkin, Nicola P
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , book chapter
  • Identifier: http://hdl.handle.net/10962/436882 , vital:73313 , ISBN 978-981-15-6370-6 , https://doi.org/10.1007/978-981-15-6370-6_8
  • Description: Supporting green skills development is integral in the transition to a green economy. Green skills can be difficult to define and measure at an aggregate level because they are a socially constructed concept, intangible and are often unobservable. Further, a demand-led approach to green skills has not worked because employers are unable to effectively articulate their needs to skills delivery bodies. This advances the need for a transformative methodology that is able to provide a more nu-anced view of skills planning to support green work. Drawing on transition theorists, this chapter demonstrates that greening work transitions occur in “niches” at local levels, where nexus concerns arise around the impetus to green work. Furthermore, it is from these transformative niches that wider social changes and regime shifts are driven or emerge. Using experiences from the chemicals sector in South Africa, the chapter illus-trates the need to develop non-reductionist conceptualisations that illustrate the “regime lock-ins” as well as green skills oppor-tunities at multiple levels.
  • Full Text:

Guest inclusion behaviour of zirconium(IV)- based polycarboxylate complexes: a study of metal-organic frameworks

  • Authors: Hulushe, Siyabonga Theophillus
  • Date: 2018
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/63710 , vital:28474
  • Description: Expected release date-April 2019
  • Full Text:

Gully erosion as a mechanism for wetland formation: an examination of two contrasting landscapes

  • Authors: Pulley, Simon , Ellery, William F N , Lagesse, Juliette V , Schlegel, P Philippa , McNamara, Shaun J
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/144410 , vital:38343 , DOI: 10.1002/ldr.2972
  • Description: Wetlands occupy broad, gently sloping valleys characterised by net deposition. Consequently, gully incision is viewed as an agent of wetland destruction. However, little attention has been given to the role of gullies in natural wetland formation. This paper determines if gully cutting and filling cycles have led to wetland formation in both an extant eroding wetland and a semi‐arid environment that once supported wetlands. At both sites, the valley fill was investigated to identify infilled gullies, and a 14C date was obtained from the gully fill.
  • Full Text:

Health and fitness of young, healthy adult females and the effect of an eight week pilates intervention

  • Authors: Eaton, Lara Lee
  • Date: 2018
  • Subjects: Physical fitness for women -- South Africa -- Makhanda , Pilates method , Exercise for women -- South Africa -- Makhanda , Exercise -- Health aspects -- South Africa -- Makhanda , Exercise -- Physiological aspects -- South Africa -- Makhanda
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/58267 , vital:27112
  • Description: Purpose: The first phase of this study aimed to investigate the health and fitness status of young adult females in the local community. The second phase of this study investigated the impact of an eight week progressive Pilates intervention on selected health and fitness parameters in this cohort. Methods: Healthy young adult females aged 18-26 years (n=96), from the local community, partook in once-off tests including anthropometric measures (stature, body mass, Body Mass Index and waist circumference) as well as fitness parameters including balance, flexibility, muscular strength and endurance, and lastly lumbo-pelvic stability. Health measures investigated included blood pressure and spirometry. Where possible, results were compared to those of similar populations from national surveys or published normative data. Sedentary volunteers from this cohort were then randomised into a Pilates Exercise (PEx, n=12) or an inactive Control (Con, n=11) group, with their results from Phase 1 serving as baseline measures. Pilates classes were held twice weekly (60 minutes per session). All the measures from phase 1 were repeated at weeks 4 and 8. An additional intervention test included Transversus abdominis recruitment. Participants maintained habitual dietary intake and energy expenditure throughout. Nine PEx group and eight Con group participants completed the intervention. Results: The current sample (phase 1) was found to be healthier than comparative populations from national surveys, and significant differences (p<0.05) were found for all comparisons except Forced Expiratory Volume (FEV1), (p=0.64). Physical activity levels (230 min.week-1) exceeded that of the recommend weekly threshold (150 min.week-1). BMI, waist circumference, blood pressure and spirometry measures were all found to be within suggested healthy normal ranges. Pilates significantly improved lumbo-pelvic stability in the PEx group at weeks 4 (p<0.005) and 8 (p<0.002). Similarly, abdominal (p=0.00, d=1.1), upper limb (p=0.037, d=0.9) and lower limb endurance (p=0.02, d=1.0, between group d=0.73 for PEx) also improved with no changes in the Con group. PEx energy expenditure significantly increased from baseline to weeks 4 (p=0.007, d=10.7) and 8 (p=0.027, d=0.64), however body mass was maintained throughout. Conversely, Minute Ventilation decreased in the PEx cohort (p=0.010, d=0.95) from weeks 4 to 8. The Con group showed significant increases in body mass (p=0.018), leg strength (within-group Cohen’s d=-1.08 between weeks 0-8; d=-2 between weeks 4-8) and dynamic balance (p=0.01, d=-0.5). While no within-group changes were observed, Protein intake was significantly greater (p=0.036, d>0.8 at baseline and week 8) in the PEx group throughout the intervention. Medium between-group effect sizes (d>0.5) were noted for PEx BMI and waist circumference measures at all time points. Further, although not significant, the large within-group effect size (d=-0.84) between baseline and week 8 for PEx systolic blood pressure, suggested the 9 mm Hg was meaningful. The same time period also indicated a large within-group effect size (d=-0.8) for PEx dynamic balance, and a medium Cohen’s d for (d=0.57) PEx static balance. Conclusion: The local population of young adult females was found to be significantly healthier than those of comparable national samples. Further, Pilates participation significantly improved lumbo-pelvic stability and muscular endurance with meaningful changes in systolic blood pressure, and balance in previously sedentary young, adult females. Body mass was also maintained.
  • Full Text:

Health education on diabetes at a South African national science festival

  • Authors: Bradshaw, Karen L , Mhlongo, M , Srinivas, Sunitha C , Marara P
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/460074 , vital:75890
  • Description: Diabetes is one of the non-communicable diseases with a major negative impact on the health and development of South Africans. Empowering the population’s understanding of the condition, with health-literacy appropriate approaches, is one of the interventions that allows discussions around the prevention of diabetes. Objective. To determine the effects of a health education programme on increasing knowledge about diabetes and encouraging preventive measures. Method. A public health education exhibition was held by a pharmacy student at a national science festival. It incorporated presentations, posters, health models, word-search games, information leaflets and a computer-based quiz consisting of pre- and post-intervention questions. Results. Junior and senior school learners participated in the computer-based quiz. Results from the junior school pre-intervention phase showed that learners had a fair prior knowledge of diabetes, with an overall score of 52.8%. Improvement in their overall mean score at the 5% significance level was noted (p=0.020). There was a significant difference in the mean score after the intervention at the 1% level (government schools: 65.5 (standard error (SE) 3.1)%, independent schools: 45.9 (6.2)%; p=0.006). Of the senior learners 53.7% (n=137) indicated that they use computers at school, while 118 (46.3%) did not have access to computers. The improvement in overall knowledge of the senior participants after the intervention was significant at the 0.1% level (p is less than 0.001). Conclusion. The health education offered by the pharmacy student's project was interactive and used an interdisciplinary approach to improve health literacy and raise awareness of diabetes. This is a tested intervention that may be adopted for improving health literacy among schoolchildren.
  • Full Text:

Hepatitis C and HIV Coinfection in Developing Countries:

  • Authors: Tastan Bishop, Özlem
  • Date: 2018
  • Language: English
  • Type: text , book
  • Identifier: http://hdl.handle.net/10962/148228 , vital:38721 , ISBN 9780128032343 , https://books.google.co.za/books?id=XSmlCgAAQBAJanddq=hepatitis+c+in+developing+countriesandsource=gbs_navlinks_s
  • Description: Because of the common routes of transmission, hepatitis C virus (HCV) coinfection with HIV is frequent. Of the 36.6 million HIV-infected individuals worldwide, about 25% are also coinfected with HCV. Developing countries face the greatest burden of coinfection. HIV infection has been shown to have a significant impact on the progression of chronic HCV, with a higher risk of cirrhosis and hepatocellular carcinoma (HCC). Because of the improvements in the management and treatment of HIV/AIDS in resource-limited countries, HCV/HIV coinfection is becoming a significant clinical problem and a major cause of morbidity and mortality. HCV/HIV coinfection is characterized by aggressive hepatic fibrogenesis, incidence of cirrhosis, and HCC. HCC is currently a major cause for liver-related deaths in HIV patients. Viral eradication has been difficult to attain with interferon and ribavirin therapies. Novel therapies with direct-acting antiviral agents have been promising for this population. However, access to such expensive regimen is far beyond the capabilities of most resource-limited countries. Yet, studies lag behind those for HCV monoinfection.
  • Full Text:

Heterodimer formation by Oct4 and Smad3 differentially regulates epithelial-to-mesenchymal transition-associated factors in breast cancer progression:

Historical analysis of leadership styles of headmasters at Kingswood College from 1993 to 2017

  • Authors: Howden, Ryan Bradley
  • Date: 2018
  • Subjects: Educational leadership -- South Africa -- Makhanda -- Case studies , Kingswood College -- History , Educational change -- South Africa -- Makhanda , School principals-- South Africa -- Makhanda , Transformational leadership -- South Africa -- Makhanda , Private schools -- Business management , Full Range Leadership
  • Language: English
  • Type: text , Thesis , Masters , MBA
  • Identifier: http://hdl.handle.net/10962/62133 , vital:28131
  • Description: A significant interest in school educational leadership has developed over the past two decades, whereby effective leadership is required in a continually changing educational environment. This study is a historical analysis of leadership styles of headmasters at Kingswood College in Grahamstown (Eastern Cape, South Africa) from 1993 to 2017. The aim is to identify leadership style(s) of headmasters using the Full Range Leadership (FRL) model as a guiding framework; to describe and interpret these style(s) in relation to the headmaster’s tenure; and to compare the headmasters’ leadership styles, noting key similarities and differences. The research method consists of interviews and a historical archival analysis. The researcher’s expectation is that headmasters will elicit a transformational leadership approach. Key findings were somewhat consistent with this hypothesis, as headmasters exhibit a general trend towards transformational leadership; although each headmaster identifies with a unique facet of transformational leadership, together with relevant supporting leadership style(s) that emerged from the data. Upon comparing headmasters, their primary leadership styles were as follows: Wilkinson identified with transactional, transformational and servant leadership; Hawke showed evidence of a transformational servant leader; Arguile elicited transformational and principle-based leadership; and Trafford depicted transformational and participative leadership. The researcher found that multiple factors in an ever-changing educational environment promoted the need for transformational leadership. The relationship between business management and educational leadership emerges as a key reflection, thus further research is required in this regard.
  • Full Text:

HIV/AIDS and other household shocks as catalysts of local commercialization of non-timber forest products in Southern Africa

  • Authors: Weyer, Dylan J , Shackleton, Charlie M , Adam, Y O
  • Date: 2018
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/398223 , vital:69385 , xlink:href="https://doi.org/10.1111/dpr.12261"
  • Description: Local trade in non-timber forest products (NTFPs) is increasing globally, yet the causes have been little studied. We examine household shock as a driver of NTFP trade in five southern African countries, with an emphasis on HIV/AIDS-related illness and death. Over the past two years, 95% of trader households experienced at least one shock, with family illness and death recorded for 68% and 42% of households, respectively. Almost 40% had entered the trade because of HIV/AIDS-related shocks. Additional shocks included natural disasters, crop pests or failure and livestock loss. The sale of NTFPs was the third most common coping strategy, after kinship and agricultural adjustments. Coping strategies differed between sites and type of shock.
  • Full Text:

Homology modeling and docking of AahII-Nanobody complexes reveal the epitope binding site on AahII scorpion toxin

  • Authors: Ksouri, Ayoub , Ghedira, Kais , Abderrazek, Rahma Ben , Shankar, B A Gowri , Benkahla, Alia , Tastan Bishop, Özlem , Bouhaouala-Zahar, Balkis
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/124604 , vital:35637 , https://doi.10.1016/j.bbrc.2018.01.036
  • Description: Scorpion envenoming and its treatment is a public health problem in many parts of the world due to highly toxic venom polypeptides diffusing rapidly within the body of severely envenomed victims. Recently, 38 AahII-specific Nanobody sequences (Nbs) were retrieved from which the performance of NbAahII10 nanobody candidate, to neutralize the most poisonous venom compound namely AahII acting on sodium channels, was established. Herein, structural computational approach is conducted to elucidate the Nb-AahII interactions that support the biological characteristics, using Nb multiple sequence alignment (MSA) followed by modeling and molecular docking investigations (RosettaAntibody, ZDOCK software tools). Sequence and structural analysis showed two dissimilar residues of NbAahII10 CDR1 (Tyr27 and Tyr29) and an inserted polar residue Ser30 that appear to play an important role. Indeed, CDR3 region of NbAahII10 is characterized by a specific Met104 and two negatively chargedresidues Asp115 and Asp117. Complex dockings reveal that NbAahII17 and NbAahII38 share one common binding site on the surface of the AahII toxin divergent from the NbAahII10 one's. At least, a couple of NbAahII10 e AahII residue interactions (Gln38 e Asn44 and Arg62, His64, respectively) are mainly involved in the toxic AahII binding site. Altogether, this study gives valuable insights in the design and development of next generation of antivenom.
  • Full Text:

HOP expression is regulated by p53 and RAS and characteristic of a cancer gene signature

  • Authors: Mattison, Stacey A , Blatch, Gregory L , Edkins, Adrienne L
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/66278 , vital:28928 , https://doi.org/10.1007/s12192-016-0755-8
  • Description: publisher version , The Hsp70/Hsp90 organising protein (HOP) is a co-chaperone essential for client protein transfer from Hsp70 to Hsp90 within the Hsp90 chaperone machine. Although HOP is upregulated in various cancers, there is limited information from in vitro studies on how HOP expression is regulated in cancer. The main objective of this study was to identify the HOP promoter and investigate its activity in cancerous cells. Bioinformatic analysis of the -2500 to +16 bp region of the HOP gene identified a large CpG island and a range of putative cis-elements. Many of the cis-elements were potentially bound by transcription factors which are activated by oncogenic pathways. Luciferase reporter assays demonstrated that the upstream region of the HOP gene contains an active promoter in vitro. Truncation of this region suggested that the core HOP promoter region was -855 to +16 bp. HOP promoter activity was highest in Hs578T, HEK293T and SV40- transformed MEF1 cell lines which expressed mutant or inactive p53. In a mutant p53 background, expression of wild-type p53 led to a reduction in promoter activity, while inhibition of wild-type p53 in HeLa cells increased HOP promoter activity. Additionally, in Hs578T and HEK293T cell lines containing inactive p53, expression of HRAS increased HOP promoter activity. However, HRAS activation of the HOP promoter was inhibited by p53 overexpression. These findings suggest for the first time that HOP expression in cancer may be regulated by both RAS activation and p53 inhibition. Taken together, these data suggest that HOP may be part of the cancer gene signature induced by a combination of mutant p53 and mutated RAS that is associated with cellular transformation.
  • Full Text: false

Hop/STIP1 depletion alters nuclear structure via depletion of nuclear structural protein emerin:

  • Authors: Kituyi, Sarah N , Edkins, Adrienne L
  • Date: 2018
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/164435 , vital:41118 , https://doi.org/10.1016/j.bbrc.2018.11.073
  • Description: Hop/STIP1 is a co-chaperone of Hsp70 and Hsp90 that regulates a number of cell biology processes via interactions with cellular proteins. Here we report a new relationship between Hop and the nuclear structural protein emerin in maintenance of nuclear morphology. Depletion or overexpression of Hop resulted in the reduction of emerin protein levels via proteasomal and lysosomal pathways.
  • Full Text:
  • Disclaimer
  • Privacy
  • Copyright
  • Contact