Enhancing the Configuration and Design of Sound Systems through Simulation
- Authors: Otten, Frederick , Foss, Richard
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427125 , vital:72416 , https://www.aes.org/e-lib/browse.cfm?elib=15848
- Description: Audio Engineers are required to design and deploy large multi-channel sound systems which meet a set of requirements and use networking technologies such as Firewire and Ethernet. Bandwidth utilsation and latency need to be considered. Network Simulation can be used to accurately model a network and return such information. This paper discusses a software system which has been developed to create a simulation of a network using the AES-X170 protocol for command and control. This system shows information about bandwidth and latency and is able to detect problems with parameter relationships. It also provides the ability to perform offline editing. These features significantly enhance audio engineers' ability to effectively design, configure and evaluate sound systems.
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Equality and unfair discrimination: refining the Harksen test
- Authors: Krüger, Rósaan
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68890 , vital:29336 , https://hdl.handle.net/10520/EJC53981
- Description: Publisher version , The 1997 formulation of the test in Harksen by Constitutional Court seemed to settle the constitutional standards in respect of equality and unfair discrimination. In this article this test is scrutinised closely with a view to clarify the different aspects of the right protected in s 9. Reliance is further placed on Canadian commentary which interrogates the dignity-centred analysis of the Canadian Supreme Court in relation to the Canadian Charter's prohibition of discrimination. The similar insistence on dignity as the interest protected by the right to equality opens up new possibilities in the South African context. Accordingly, specific 'wrongs' or 'indignities' of inequality are identified, which refines the Harksen test. The identification of the indignities, it is suggested, assists litigants and the court on a practical level when determining the fairness or otherwise of discrimination.
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Evaluating The Potential Contribution Of Episodic Toxicity Data To Environmental Water Quality Management In South Africa
- Authors: Gordon, Andrew K , Mantel, Sukhmani K , Muller, Nikite W J
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , report
- Identifier: http://hdl.handle.net/10962/438310 , vital:73450 , ISBN 978-1-4312-0070-2 , https://wrcwebsite.azurewebsites.net/wp-content/uploads/mdocs/KV259-10.pdf
- Description: An important aspect of the dynamics of nutrients and pollutants in natural systems is captured in the concept of allochthony, founded on the observation that nutrients and energy in a variety of forms are transferred between adjacent habitats, com-munities and ecosystems that are not routinely considered as connected. Different forms of nutrients and energy move across the conceptual boundaries of habitats via organisms’ activities or physical processes such as wind or water currents, and these transfers can represent important food subsidies. Such cross-partition ecolog-ical subsidies can augment the nutritional condition, biomass and biodiversity of communities, particularly where local production (or autochthony) alone may be inadequate to support local food webs. Furthermore, organic subsidies can influ-ence population dynamics, community interactions and ecosystem processes, and can represent dominant flux inputs in ecosystem budgets. Our intention was to explore organic nutrient fluxes in relation to a primarily lotic (i.e. flowing) aquatic sys-tem at the scale of a hydrological catchment.
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Evaluation of the in vitro differential protein adsorption patterns of didanosine-loaded nanostructured lipid carriers (NLCs) for potential targeting to the brain
- Authors: Kasongo, Kasongo W , Jansch, Mirko , Müller, Rainer H , Walker, Roderick B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184035 , vital:44160 , xlink:href="https://doi.org/10.3109/08982104.2010.539186"
- Description: The preferential in vitro adsorption of apolipoprotein E (Apo E) onto the surface of colloidal drug carriers may be used as a strategy to evaluate the in vivo potential for such systems to transport drugs to the brain. The aim of this research was to investigate the in vitro protein adsorption patterns of didanosine-loaded nanostructured lipid carriers (DDI-NLCs), using two-dimensional polyacrylamide gel electrophoresis (2-D PAGE), in order to establish the potential for NLCs to deliver DDI to the brain. NLC formulations were manufactured using high-pressure homogenization using a lipid matrix consisting of a mixture of Precirol® ATO 5 and Transcutol® HP. The 2-D PAGE analysis revealed that NLCs in formulations stabilized using Solutol® HS 15 alone or with a ternary surfactant system consisting of Solutol® HS 15, Tween® 80, and Lutrol® F68, preferentially adsorbed proteins, such as Apo E. Particles stabilized with Tween® 80 and Lutrol® F68 did not adsorb Apo E in these studies, which could be related to the relatively large particle size and hence small surface area observed for these NLCs. These findings have revealed that DDI-loaded NLCs may have the potential to deliver DDI to the brain in vivo and, in addition, to Tween® 80, which has already been shown to have the ability to facilitate the targeting of colloidal drug delivery systems to the brain. Solutol® HS 15–stabilized nanoparticles may also achieve a similar purpose.
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Evaluation of the kinetics and mechanism of drug release from Econazole nitrate nanosponge loaded Carbapol Hydrogel
- Authors: Sharma, Renuka , Walker, Roderick B , Pathak, Kamla
- Date: 2011
- Language: English
- Type: text , Article
- Identifier: vital:6437 , http://hdl.handle.net/10962/d1006614
- Description: The objective of this study was to investigate the mechanism of release of econazole nitrate (EN) nanosponges loaded hydrogel and to compare it with EN hydrogel so as to develop an extended release topical drug delivery system of EN. Nanosponges of EN were prepared using ethyl cellulose and PVA by emulsion solvent evaporation method. On the basis of pharmacotechnical evaluation nanosponges with least particle size of 230.1 nm and good rheological properties were formulated as hydrogel (F1 – F7). In vitro drug release data of EN nanosponges loaded hydrogels in phosphate buffer pH 6.8 and 7.4 when analysed by GraphPad Prism software version 4.0 San Diego, USA best fitted the Makoid-2 Banakar model (R value greater than 0.98). The Korsmeyer-Peppas release exponent (n) ranged between 0.331 – 0.418, which confirmed diffusion as the principle mechanism of drug release. The release mechanism was further confirmed by calculating the ratio of exponents A/B ratio derived from the Kopcha model.
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Extending legal professional privilege to non-legal tax practitioners in South Africa: a comparative and constitutional perspective
- Authors: Jani, Pride
- Date: 2011
- Language: English
- Type: text , Thesis , Masters , MCom
- Identifier: vital:882 , http://hdl.handle.net/10962/d1001636
- Description: This study explains the differing rights of taxpayers, based on the nature of the profession of the tax adviser they consult. Those who utilize the services of tax attorneys can rely on the protection afforded by legal professional privilege whereas those who obtain their advice from non-legal advisers, such as accountants and other tax advisers, cannot claim the same protection. Legal professional privilege is a substantive right which should be extended to cover clients of non-legal tax advisers. The continued denial of the privilege to clients of nonlegal tax practitioners while it is availed to those who approach legal practitioners infringes the rights to privacy and equality contained in the South African Constitution. The object of this research is to show that the common law concept of legal professional privilege is amenable to extension so as to cover the clients of non-legal tax advisers. A qualitative approach was adopted which involved an in-depth analysis of the origins, rationale as well as the requirements for the operation of the doctrine. This also involved a constitutional as well as a comparative dimension. The constitutional dimension sought to show that the current distinction is untenable under the South African Constitution by virtue of the infringement of the rights to privacy and equality. The comparative dimension presented an analysis of the various jurisdictions that have extended the doctrine as well as those that are still to do so or have adamantly rejected the idea. The differential treatment of taxpayers based on the professional they engage contravenes the privacy and equality provisions and is thus unconstitutional. The study demonstrates that legal professional privilege is amenable to extension and there is need for legislative intervention as the courts are limited in the extent to which they may intervene in light of the separation of powers and judicial deference. Legal professional privilege should therefore be extended to protect the clients of non-legal tax advisers as opposed to partial protection which subsists at the moment.
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First assessment of estuarine space use and home range of juvenile white steenbras, Lithognathus lithognathus
- Authors: Bennett, Rhett H , Childs, Amber-Robyn , Cowley, Paul D , Næsje, T F , Thorstad, Eva B , Økland, F
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447517 , vital:74653 , https://doi.org/10.1080/15627020.2011.11407476
- Description: The spatial dynamics and home range sizes of early juvenile white steenbras (Lithognathus lithognathus Cuvier, 1829) in the permanently open Great Fish Estuary, South Africa, were assessed using acoustic telemetry. Seven individuals (154–184 mm fork length) tagged with acoustic transmitters spent the majority of their time in the mesohaline to oligohaline regions of the estuary, between five and seven kilometres from the mouth. Mean home range size was small (97 399 ± 22 557 m2, mean ± S.D.) relative to the size of the estuary (approx. 1 360 000m2). Mean length of the estuary used by an individual was 1707m(±S.D.=1663 m). The fish were highly resident within the estuary, and showed fidelity towards their site of capture.
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Forged in the heat: doing journalism
- Authors: Stewart, Gavin
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454696 , vital:75367 , https://hdl.handle.net/10520/EJC135804
- Description: Cue's instant success in 1987 came from a coincidence of events and places around, as much as inside, the Department of Journalism and Media Studies at Rhodes University.
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Formation, surface characterization, and electrocatalytic application of self-assembled monolayer films of tetra-substituted manganese, iron, and cobalt benzylthio phthalocyanine complexes
- Authors: Akinbulu, Isaac Adebayo , Ozoemena, Kenneth Iyke , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247163 , vital:51552 , xlink:href="https://doi.org/10.1007/s10008-010-1243-1"
- Description: Molecular thin films of manganese (SAM-2), iron (SAM-3), and cobalt (SAM-4) phthalocyanine complexes, non-peripherally tetra-substituted with benzylmercapto, were formed on polycrystalline gold disc electrode by self-assembly technique. Surface characteristics of the films were interrogated by cyclic voltammetry. Significant passivation of voltammetry processes associated with bare gold surface (gold oxidation and underpotential deposition of copper) confirmed formation of the films. Electrocatalytic property of the films was evidenced from better voltammetry responses (less positive oxidation potential and better current signal) of the insecticide, carbofuran, on these films, relative to that on bare gold electrode. In terms of less positive oxidation potential, the FePc derivative (3) gave the best response, while the best current signal was observed on SAM-2-modified gold electrode. The average heterogeneous rate constant, k, for the oxidation of carbofuran was 3.6 × 10−2 cm s−1 on the SAM film with the best current signal (SAM-2).
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Formulation development and in vitro evaluation of didanosine-loaded nanostructured lipid carriers for the potential treatment of AIDS dementia complex
- Authors: Wa Kasongo, Kasongo , Shegokar, Ranjita , Müller, Rainer H , Walker, Roderick B
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184210 , vital:44190 , xlink:href="https://doi.org/10.3109/03639045.2010.516264"
- Description: The purpose of this article was to investigate the feasibility of incorporating didanosine (DDI) into nanostructured lipid carriers (NLC) for potential treatment of AIDS dementia complex. Aqueous DDI-free and DDI-loaded NLC were manufactured using hot high-pressure homogenization. The lipid matrix contained a mixture of Precirol ® ATO 5 and Transcutol ® HP. Photon correlation spectroscopy revealed that the mean particle size for all formulations was below 250 nm with narrow polydispersity indices. In addition, the d99% values for all formulations determined using laser diffractometry were below 400 nm with the span values ranging from 0.84 to 1.0. The zeta potential values ranged from −18.4 to −11.4 mV and the encapsulation efficiency of NLC for DDI ranged from 33.02% to 78.34%. These parameters remained relatively constant for all formulations tested following storage for 2 months at 25°C indicating that all the formulations were relatively stable. Differential scanning calorimetry revealed a decrease in the degree of crystallinity of NLC in all formulations developed relative to the bulk lipid material. In addition, wide-angle X-ray scattering showed that NLC in all formulations tested existed in a single β-modification form and that DDI that had been incorporated into the NLC appeared to be molecularly dispersed in the lipid matrices. Images of the NLC formulations obtained using transmission electron microscopy revealed that all formulations contained a mixture of spherical and nonspherical particles irrespective of the amount of DDI that was added during the manufacture of the formulations.
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From Oral Literature to Technauriture: What’s in a Name?
- Authors: Kaschula, Russell H , Mostert, André M
- Date: 2011
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/175201 , vital:42552 , ISBN 978-0-9566052-3-8 , https://aspace.repository.cam.ac.uk/handle/1810/237322
- Description: Oral traditions and oral literature have long contributed to human communication, yet the advent of arguably the most influential technology—the written word—altered the course of creative ability. Despite its potential and scope, the development of the written word resulted in an insidious dichotomy. As the written word evolved, the oral word became devalued and pushed to the fringes of society. One of the unfortunate consequences of this transition to writing has been a focus on the systems and conventions of orality and oral tradition. Although of importance, a more appropriate focus would be on ways of supporting and maintaining the oral word, and its innate value to human society, in the face of rampant technological development. Yet it is ironic that technology is also helping to create a fecund environment for the rebirth of orality. This paper offers an overview of the debate about the relationship between oral literature, the written word and technology, and suggests that the term technauriture may offer a suitable encompassing paradigm for further engagement with the oral word and its application to modern society. We discuss the late Bongani Sitole, a poet whose oral works were transformed into public and educational resources through the application of technology, and we consider the utility of the term technauriture for describing the relationship between orality, literature and technology.
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Gender and Racial Stereotyping in Rape Coverage: An analysis of rape coverage in a South African newspaper, Grocott’s Mail
- Authors: Bonnes, Stephanie M
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453321 , vital:75245 , https://doi.org/10.1080/14680777.2011.623170
- Description: This article uses critical discourse analysis to discuss and analyse articles about rape that appeared in a South African newspaper, Grocott's Mail, between 14 October, 2008 and 29 October, 2009. Drawing on existing literature on “rape myths” in media coverage of rape, this article argues that Grocott's Mail perpetuates racial and gender stereotypes through the way in which it reports on rape. While not all of the articles included in the analysis use rape myths, most use one or more when discussing rape incidents. Specifically, Grocott's Mail tends to use rape myths that blame the victim for the rape and de-emphasise the role of the perpetrator in the rape.
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Geographic variation in the trophic ecology of an avian rocky shore predator, the African black oystercatcher, along the southern African coastline
- Authors: Kohler, Sophie A , Connan, Maëlle , Hill, Jaclyn M , Mablouké, Cécile , Bonnevie, Bo T , Ludynia, Katrin , Kemper, Jessica , Huisamen, Johan , Underhill, Leslie G , Cherel, Yves , McQuaid, Christopher D , Jaquemet, Sébastien
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444576 , vital:74252 , https://doi.org/10.3354/meps09215
- Description: The reflection of baseline isotopic signals along marine food chains up to higher trophic levels has been widely used in the study of oceanic top predators but rarely for intertidal predators. We investigated variation in the δ 13 C and δ 15 N ratios of a sedentary, rocky shore predator, the African black oystercatcher Haematopus moquini, over~ 2000 km of the southern African coastline, which is characterized by strong biogeographic patterns in primary productivity and intertidal communities. Blood and feathers from breeding adults and chicks and muscle tissues from primary prey items (mussels and limpets) were sampled between southern Namibia and the southeast coast of South Africa. 15 N enrichment was observed between the southeast and west coasts in oystercatcher tissues and their prey, mirroring an isotope shift between the oligotrophic Agulhas Current on the east coast and the eutrophic Benguela upwelling system on the west coast.
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Going against the tide: seeking regulations for private military/security companies in a globalized world
- Authors: Juma, Laurence
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/128822 , vital:36163 , https://hdl.handle.net/10520/EJC85398
- Description: This article discusses the role of privatization of security in Africa, but its focus is on private military and security companies (PMSCs). The article proceeds on the basis that there is need for effective regulatory frameworks for PMSCs that operate in conflict zones of Africa. Thus, it begins by appraising the existing normative standards at the international, regional and domestic level that apply to these companies, and thereafter, identifies their shortcomings in light of the prevailing security conditions within the continent. The article then posits broad theoretical imperatives for designing a more effective regulatory framework for PMSCs and concludes by proposing the establishment an overarching continental regime constructed on the basis of the suggested imperatives.
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Good Chemistry
- Authors: Grange, Helen
- Date: 2011
- Subjects: Nyokong, Tebello , Africa-Arab State 2009 Unesco-L'Oreal Award for Women in Science
- Language: English
- Type: Article , text
- Identifier: vital:7185 , http://hdl.handle.net/10962/d1006276 , Nyokong, Tebello , Africa-Arab State 2009 Unesco-L'Oreal Award for Women in Science
- Description: Helen Grange profiles four women who've fearlessly taken on the complex predominantly male-dominated field of science.
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Heritage–A conceptually evolving and dissonant phenomenon: Implications for heritage management and education practices in post-colonial Southern Africa
- Authors: Zazu, Clayton
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387208 , vital:68215 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122250"
- Description: This conceptual paper is based on experiences and insights which have emerged from my quest to develop a conceptual framework for working with the term ‘heritage’ within an education for sustainable development study that I am currently conducting. Of specific interest to me, and having potential to improve the relevance and quality of heritage education in southern Africa, given the region’s inherent cultural diversity and colonial history, is the need for ‘heritage construct inclusivity’ within the processes constituting heritage education practices. Working around this broad research goal, I therefore needed to be clear about what I mean or refer to as heritage. I realised, however, how elusive and conceptually problematic the term ‘heritage’ is. I therefore, drawing from literature and experiences gained during field observations and focus group interviews, came up with the idea of working with three viewpoints of heritage. Drawing on real life cases I argue that current heritage management and education practices’ failure to recognise and respect the evolving, interconnectedness and multi layered nature of heritage, partly explain the same practices’ lack of relevance and agency to enhance the sustainable management of local heritage resources. I also suggest a few ideas which heritage educators in the context of post-colonial southern Africa may need to consider in their everyday heritage education practices. I also introduce the notion of conceptualising heritage as ‘cultural landscapes’, within which the evolving, dissonant and interconnected nature of heritage, and associated heritage constructs, may be reconciled.
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Hierarchical spatial organization and prioritization of wetlands: a conceptual model for wetland rehabilitation in South Africa
- Authors: Sieben, E J J , Ellery, William F N , Kotze, Donovan C , Rountree, M
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/144399 , vital:38342 , DOI: 10.1007/s11273-011-9212-8
- Description: Wetland rehabilitation planning needs to take into account many different aspects of the wetland and its context. In South Africa, much emphasis is placed on the delivery of ecosystem services, poverty relief and skills development for those involved in labour-intensive rehabilitation measures. A framework is presented that facilitates decision-making with regards to wetland rehabilitation planning. This starts with prioritizing which wetlands need attention within a catchment. This is followed by decisions regarding which rehabilitation measures would be effective in improving certain ecosystem services based upon the aims of rehabilitation and the social context of the surrounding catchment.
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High Speed Lexical Classification of Malicious URLs
- Authors: Egan, Shaun P , Irwin, Barry V W
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428055 , vital:72483 , https://www.researchgate.net/profile/Barry-Ir-win/publication/326225046_High_Speed_Lexical_Classification_of_Malicious_URLs/links/5b3f20acaca27207851c60f9/High-Speed-Lexical-Classification-of-Malicious-URLs.pdf
- Description: It has been shown in recent research that it is possible to identify malicious URLs through lexi-cal analysis of their URL structures alone. Lightweight algorithms are defined as methods by which URLs are analyzed that do not use external sources of information such as WHOIS lookups, blacklist lookups and content analysis. These parameters include URL length, number of delimiters as well as the number of traversals through the directory structure and are used throughout much of the research in the paradigm of lightweight classification. Methods which include external sources of information are often called fully featured classifications and have been shown to be only slightly more effective than a purely lexical analysis when considering both false-positives and falsenegatives. This distinction allows these algorithms to be run client side without the introduction of additional latency, but still providing a high level of accuracy through the use of modern techniques in training classifiers. Both AROW and CW classifier update methods will be used as prototype implementations and their effectiveness will be com-pared to fully featured analysis results. These methods are selected because they are able to train on any labeled data, including instances in which their prediction is correct, allowing them to build a confidence in specific lexical features.
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Hsp90α/β associates with the GSK3β/axin1/phospho-β-catenin complex in the human MCF-7 epithelial breast cancer model:
- Authors: Cooper, Leanne C , Prinsloo, Earl , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165096 , vital:41208 , DOI: 10.1016/j.bbrc.2011.08.136
- Description: Hsp90α/β, the signal transduction chaperone, maintains intracellular communication in normal, stem, and cancer cells. The well characterised association of Hsp90α/β with its client kinases form the framework of multiple signalling networks. GSK3β, a known Hsp90α/β client, mediates β-catenin phosphorylation as part of a cytoplasmic destruction complex which targets phospho-β-catenin to the 26S proteasome. The canonical Wnt/β-catenin pathway promotes stem cell self-renewal as well as oncogenesis. The degree of Hsp90α/β involvement in Wnt/β-catenin signalling needs clarification. Here, we describe the association of Hsp90α/β with GSK3β, β-catenin, phospho-β-catenin and the molecular scaffold, axin1, in the human MCF-7 epithelial breast cancer cell model using selective inhibition of Hsp90α/β, confocal laser scanning microscopy and immunoprecipitation. Our findings suggest that Hsp90α/β modulates the phosphorylation of β-catenin by interaction in common complex with GSK3β/axin1/β-catenin.
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Human DNAJ in cancer and stem cells:
- Authors: Sterrenberg, Jason N , Edkins, Adrienne L , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165118 , vital:41210 , DOI: 10.1016/j.canlet.2011.08.019
- Description: The heat shock protein 40 kDa (HSP40/DNAJ) co-chaperones constitute the largest and most diverse sub-group of the heat shock protein (HSP) family. DNAJ are widely accepted as regulators of HSP70 function, but also have roles as co-chaperones for the HSP90 chaperone machine, and a growing number of biological functions that may be independent of either of these chaperones. The DNAJ proteins are differentially expressed in human tissues and demonstrate the capacity to function to both promote and suppress cancer development by acting as chaperones for tumour suppressors or oncoproteins. We review the current literature on the function and expression of DNAJ in cancer, stem cells and cancer stem cells. Combining data from gene expression, proteomics and studies in other systems, we propose that DNAJ will be key regulators of cancer, stem cell and possibly cancer stem cell function. The diversity of DNAJ and their assorted roles in a range of biological functions means that selected DNAJ, provided there is limited redundancy and that a specific link to malignancy can be established, may yet provide an attractive target for specific and selective drug design for the development of anti-cancer treatments.
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