15 research outputs found

    The different roles of ‘design process champions’ for digital libraries in African higher education

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    The concept of design stakeholders is central to effective design of digital libraries. We report on research findings that identified the presence of a key subset of stakeholders which we term ‘design process champions’. Our findings have identified that these champions can change interaction patterns and the eventual output of the other stakeholders (project participants) in the design process of digital library projects. This empirical research is based upon 38 interviews with key stakeholders and a review of documentary evidence in ten innovative digital library design projects (e.g. mobile clinical libraries) located in three African universities in Kenya, Uganda and South Africa. Through a grounded theory approach two different types of the ‘design process champions’ emerged from the data with varying levels of effectiveness in the design process: (i) domain champions and (ii) multidisciplinary champions. The domain champions assume a ‘siloed’ approach of engagement while the multidisciplinary champions take on a participatory engagement throughout the design process. A discussion of the implications of information specialists functioning as domain champions is highlighted. We conclude by suggesting that the multidisciplinary champions’ approach is particularly useful in supporting sustainability of digital library design projects

    Enhancing Jatropha oil extraction yield from the kernels assisted by a xylan-degrading bacterium to preserve protein structure

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    We investigated the use of bacterial cells isolated from paddy crab for the extraction of oil from Jatropha seed kernels in aqueous media while simultaneously preserving the protein structures of this protein-rich endosperm. A bacterial strain—which was marked as MB4 and identified by means of 16S rDNA sequencing and physiological characterization as either Bacillus pumilus or Bacillus altitudinis—enhanced the extraction yield of Jatropha oil. The incubation of an MB4 starter culture with preheated kernel slurry in aqueous media with the initial pH of 5.5 at 37 °C for 6 h liberated 73% w/w of the Jatropha oil. Since MB4 produces xylanases, it is suggested that strain MB4 facilitates oil liberation via degradation of hemicelluloses which form the oil-containing cell wall structure of the kernel. After MB4 assisted oil extraction, SDS-PAGE analysis showed that the majority of Jatropha proteins were preserved in the solid phase of the extraction residues. The advantages offered by this process are: protein in the residue can be further processed for other applications, no purified enzyme preparation is needed, and the resulting oil can be used for biodiesel production

    Return to work of breast cancer survivors: a systematic review of intervention studies

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    <p>Abstract</p> <p>Background</p> <p>Breast cancer management has improved dramatically in the past three decades and as a result, a population of working age women is breast cancer survivor. Interventions for breast cancer survivors have shown improvements in quality of life and in physical and psychological states. In contrast, efforts aimed at stimulating re-employment and return-to-work interventions for breast cancer survivors have not kept pace. The objective of this review was to study the effects and characteristics of intervention studies on breast cancer survivors in which the outcome was return to work.</p> <p>Methods</p> <p>The Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2006), Medline, Ovid, EMBASE and PsychInfo were systematically searched for studies conducted between 1970 to February 2007. Intervention studies for female breast cancer survivors that were focused on return to work were included.</p> <p>Results</p> <p>Our search strategy identified 5219 studies. Four studies out of 100 potentially relevant abstracts were selected and included 46–317 employed women who had had mastectomy, adjuvant therapy and rehabilitation, with the outcome return to work. The intervention programs focused on improvement of physical, psychological and social recovery. Although a substantial percentage (between 75% to 85%) of patients included in these studies returned to work after rehabilitation, it is not clear whether this proportion would have been lower for patients without counseling or exercise, or any other interventions, as three out of four studies did not include a comparison group.</p> <p>Conclusion</p> <p>The most important finding of this review is the lack of methodologically sound intervention studies on breast cancer survivors with the outcome return to work. Using evidence from qualitative and observational studies on cancer and the good results of intervention studies on return to work programs and vocational rehabilitation, return to work interventions for breast cancer survivors should be further developed and evaluated.</p

    Valorisation of sawdust through the combined microwave-assisted hydrothermal pre-treatment and fermentation using an oleaginous yeast

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    Oleaginous yeast, cultured on second-generation lignocellulosic resources, has the potential to be a key part of the future energy sector. However, the multiple unit operations necessary to produce concentrated hydrolysates, with a minimum of fermentation inhibitors, limit the applicability to date. In this study, a simple microwave-assisted hydrothermal pre-treatment step of oak or beech sawdust was deployed to produce an oligosaccharide-rich hydrolysate. This was then catabolised by the oleaginous yeast, Metschnikowia pulcherrima, avoiding the need for costly enzymatic or further chemical steps in the processing. Up to 85% of the sawdust’s hemicelluloses could be solubilised under these conditions, and 8 g/L DCW yeast with a 42% lipid content produced. While a number of studies have demonstrated that oleaginous yeasts possess high inhibitor tolerance, using this real lignocellulosic hydrolysate, we demonstrate that lipid production is actually very sensitive to inhibitor and carbon availability, and the optimal system is not the one that gives the highest hydrolysate or cell biomass. Indeed, the yeast was shown to detoxify the inhibitors in the process, but at high inhibitor loading, this leads to very poor lipid production, especially at high furfural levels. These findings clearly highlight the importance of considering multiple variables when real, complex lignocellulosic media are involved, tuning process conditions based on the desired fermentation outcomes

    Characterization of the beta-glucosidase activity produced by enological strains of non-saccharomyces yeasts

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    The beta-glucosidase activities of 20 wine-related non-Saccharomyces yeasts were quantified, characterized,and assessed for their efficiency in releasing aroma-enhancing compounds during the winemaking process. Of these enzymatic activities, the beta-glucosidase activity of Debaryomyces pseudopolymorphus revealed the most suitable combination of properties in terms of functionality at wine pH, resistance to wine-associated inhibitory compounds (glucose, ethanol, and sulfur dioxide), high substrate affinity, and large aglycone-substrate recognition. Its potential as a wine aroma–enhancing enzyme was confirmed by the significantly increasing concentrations of free volatiles (citronellol, nerol, and geraniol) during the fermentation of Chardonnay juice inoculated with both D. pseudopolymorphus and a widely used commercial starter culture strain of Saccharomyces cerevisiae, VIN13.R.R. Cordero Otero, J.F. Ubeda Iranzo, A.I. Briones-Perez, N. Potgieter, M.A. Villena, I.S. Pretorius, and P. van Rensbur

    Hepatite crônica por vírus C: Parte 1. Considerações gerais Hepatitis C virus: Part 1. General considerations

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    O vírus da hepatite C foi identificado em 1989 como sendo o principal agente causador das hepatites não-A não-B e o seu reconhecimento como agente de alta prevalência nas infecções pós-tranfusionais e/ou uso de derivados do sangue ou em associação com o abuso de drogas endovenosas. A descoberta e a maior disponibilidade de novas técnicas para a seleção adequada de doadores de sangue, reduziu sensivelmente a incidência das hepatites pós-transfusionais. Cerca de 95% dos indivíduos infectados pelo vírus da hepatite C podem ser identificados pelos testes anti-vírus da hepatite C de terceira geração. Os estudos retrospectivos de infecções pelo vírus da hepatite C iatrogênicas, são as principais fontes de reconhecimento da história natural da doença. A distribuição dos diferentes genótipos do vírus da hepatite C varia de acordo com as regiões geográficas. Na América do Sul, Europa, Estados Unidos e Japão 1, 2, e 3 representam a maioria das infecções, sendo o subtipo 1-b o mais prevalente. Os parâmetros epidemiológicos (idade, fatores de risco e duração da infecção) podem estar associados com os genótipos do vírus da hepatite C, sendo os tipos 1-a e 3-a mais freqüentes nos drogaditos endovenosos e o 1-b nas hepatites pós-transfusionais. O subtipo 1-b ocasiona lesões hepáticas mais graves e prolongadas, com alterações ultraestruturais mitocondriais freqüentes e grande comprometimento dos processos de fosforilização oxidativa. A produção aumentada de radicais livres pode influenciar negativamente a evolução da doença hepática pelo reforço da ação citopática do vírus da hepatite C que provoca. O significado clínico dos níveis de vírus C no interior do fígado, nesses pacientes, não é determinado pelos fatores hospedeiro (idade, tipo e duração da infecção) ou pelos fatores virais (genótipos) e os repetidamente vírus da hepatite C RNA RT-PCR negativos no soro, não indicam necessariamente ausência de vírus da hepatite C no fígado. A associação de autoimunidade à hepatite C é questionável. Os marcadores imunes são freqüentemente detectados em baixos níveis. A modulação da resposta imune ao envelope protéico E2, após injeção de plasmídios DNA, tem sido usada para induzir respostas imunes específicas ao vírus da hepatite C. O espectro de tais respostas poderia ser ampliada mediante combinação de plasmídios, vias de administração e outras formas de imunógenos codificados (vacinas a base de peptídios). Tais estratégias podem vir a ser importantes, em breve, no combate aos altamente mutantes vírus da hepatite C. O papel patogênico dos novos vírus G e TT das hepatites está em estudos, porém é de consenso que suas associações com doença hepática ativa é fortuita.<br>Hepatitis C virus was identified in 1989 as the main causative agent of non-A, non-B and was followed by the recognition of a high prevalence of hepatitis C virus infection after transfusion of infected blood or blood products and in association with intravenous drug abuse. The availability of sensitive and reliable techniques to screen blood for hepatitis C virus has reduced the incidence of post-transfusion hepatitis. True healthy carriers of hepatitis C virus did not exist. Aproximately 95% of hepatitis C virus infected individuals can be identified by third generation anti- hepatitis C virus testing. Retrospective studies of iatrogenic hepatitis C virus infection are the main source of the natural history of the disease. The distribution of different hepatitis C virus genotypes varies according to the grographic region. In South America, Europe, The United States and Japan hepatitis C virus genotypes 1, 2 and 3 account for the majority of the infections, being (sub)type 1b the most prevalent. Epidemiological parameters (age, risk factors and duration of infection) may be associated with hepatitis C virus genotypes (intravenous drug abuse with types 1-a and 3-a and 1-b with post-transfusion hepatitic C). Subtype 1-b, lead to a more severe course of viral infection, with ultrastructural alterations of the mitochondria, and greater impairment of the process of oxidative phosphorylation. No increased production of free radicals may influence the evolution of the liver disease by an enhancement of the cytopathic effect of hepatitis C virus. The clinical significance of intrahepatic hepatitis C virus level in patients with chronic hepatitis C virus infection is not determined by host factors (age of patient, mode or duration of infection) or by virus factors (hepatitis C virus genotypes) and, repeatedly negative RT-PCR for hepatitis C virus RNA in serum does not indicate absence of hepatitis C virus from the liver. The association between autoimmunity and hepatitis C virus is questioned. Markers of its does occur with high frequency in these patients. Modulation of immune responses to hepatitis C virus envelope E2 protein following injection of plasmid DNA, has been used for induction of specific response to hepatitis C virus. The spectrum of such responses could likely be broadened by combining plasmids, delivery routes, and other forms of encoded immunogens (peptide vaccines). These may be important to the development of a vaccine against the high mutable hepatitis C virus. The pathogenic role of novel DNA virus (TTV) is under spotlight. As with hepatitis G, however, the association of TTV with disease is far from clear
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