598 research outputs found
Development of a novel automated perfusion mini bioreactor âambrÂź 250 perfusion
In recent years a strong trend towards continuous biopharmaceutical processing has gathered momentum, driven by the promise of process intensification, reduced cost of goods, and more consistent and better controlled product quality. Key technologies in upstream cell culture (ATF, TFF) have enabled the start of a shift towards process intensification/continuous processing in the seed train (N-1 perfusion) and main production culture (concentrated fed-batch, perfusion) for biopharmaceutical production processes. While these technologies are now available for large scale bioreactor operations, small-scale application is limited to traditional benchtop bioreactor scales and formats. Benchtop bioreactors do provide a route to developing this new wave of intensified/continuous cell culture processes, however this approach is manually intensive, relatively low throughput and cost-intensive to operate. In the last 5 years, fed-batch cell culture process development has been significantly accelerated by wide spread implementation of the ambr 15 and ambr 250 fully automated, single-use, micro and mini bioreactor systems. Case studies will be presented on the utility of the ambr 15 as a perfusion mimic, and we also present here the first publication of a new version of the ambr 250 system currently in development âambr 250 perfusionâ. Technical description and operating data presented for the novel âambr 250 perfusionâ system outline the capacity and capability of this technology. As established with ambr 250 for fed-batch processes, ambr 250 perfusion has the potential to provide the industry with a step change in perfusion process development capacity, enabling implementation of DoE based approaches for process optimization and characterization. It is envisaged that âambr 250 perfusionâ can therefore facilitate and significantly accelerate an industry wide transition to upstream cell culture perfusion processes for novel biopharmaceuticals currently in early development
Plastic pollution: why is it a public health problem?
Derived from petrochemicals,1 plastics are composed of monomers that are sequenced into polymer chains. Since their commercial development in the 1930s and 1940s, the modern world has become hugely reliant on plastics. They have extensively replaced wood, metal, ceramics and glass in manufacture and construction. They are embedded in the economic system and our daily lives. There are many different types of plastic with different potentials to be reused or recycled (Box 1).
Phosphorylation of U24 from Human Herpes Virus type 6 (HHV-6) and its potential role in mimicking myelin basic protein (MBP) in multiple sclerosis
AbstractMyelin basic protein (MBP) from multiple sclerosis (MS) patients contains lower levels of phosphorylation at Thr97 than normal individuals. The significance of phosphorylation at this site is not fully understood, but it is proposed to play a role in the normal functioning of MBP. Human Herpesvirus Type 6 encodes the protein U24, which has tentatively been implicated in the pathology of MS. U24 shares a 7 amino acid stretch encompassing the Thr97 phosphorylation site of MBP: PRTPPPS. We demonstrate using a combination of mass spectrometry, thin layer chromatography and autoradiography, that U24 can be phosphorylated at the equivalent threonine. Phospho-U24 may confound signalling or other pathways in which phosphorylated MBP may participate, precipitating a pathological process.Structured summaryMINT-6613181:MAPK (uniprotkb:P28482) phosphorylates (MI:0217) MBP (uniprotkb:P02687) by protein kinase assay (MI:0424)MINT-6613171, MINT-6613190:MAPK (uniprotkb:P28482) phosphorylates (MI:0217) U24 (uniprotkb:Q69559) by protein kinase assay (MI:0424
Development of a novel automated perfusion mini-bioreactor ambrÂź 250 perfusion
Session proposals: Towards other cell lines and systems â opportunities and challenges beyond CHO cells Pushing the Limits on Process Intensification: 10 grams/Liter and Beyond Process Scale Up/Down, Characterization and Control Strategy Definition In recent years a strong trend towards continuous biopharmaceutical processing has gathered momentum, driven by the promise of process intensification, reduced cost of goods, and more consistent and better controlled product quality. Key technologies in upstream cell culture (ATF, TFF) have enabled the start of a shift towards process intensification/continuous processing in the seed train (N-1 perfusion) and main production culture (concentrated fed-batch, perfusion) for biopharmaceutical production processes. While these technologies are now available for large scale bioreactor operations, small-scale application is limited to traditional benchtop bioreactor scales and formats. Benchtop bioreactors do provide a route to developing this new wave of intensified/continuous cell culture processes, however this approach is manually intensive, relatively low throughput and cost-intensive to operate. In the last 5 years, fed-batch cell culture process development has been significantly accelerated by wide spread implementation of the ambr 15 and ambr 250 fully automated, single-use, micro and mini bioreactor systems. Case studies will be presented on the utility of the ambr 15 as a perfusion mimic, and we also present here novel performance data of a new version of the ambr 250 system âambr 250 perfusionâ. Technical description and operating data and cell culture results presented for the novel âambr 250 perfusionâ system outline the capacity and capability of this technology. As established with ambr 250 for fed-batch processes, ambr 250 perfusion has the potential to provide the industry with a step change in perfusion process development capacity, enabling implementation of DoE based approaches for process optimization and characterization. It is envisaged that âambr 250 perfusionâ can therefore facilitate and significantly accelerate an industry wide transition to upstream cell culture perfusion processes for novel biopharmaceuticals currently in early development
The emergence of resistance to the benzimidazole anthlemintics in parasitic nematodes of livestock is characterised by multiple independent hard and soft selective sweeps
Anthelmintic resistance is a major problem for the control of parasitic nematodes of livestock and of growing concern for human parasite control. However, there is little understanding of how resistance arises and spreads or of the âgenetic signatureâ of selection for this group of important pathogens. We have investigated these questions in the system for which anthelmintic resistance is most advanced; benzimidazole resistance in the sheep parasites Haemonchus contortus and Teladorsagia circumcincta. Population genetic analysis with neutral microsatellite markers reveals that T. circumcincta has higher genetic diversity but lower genetic differentiation between farms than H. contortus in the UK. We propose that this is due to epidemiological differences between the two parasites resulting in greater seasonal bottlenecking of H. contortus. There is a remarkably high level of resistance haplotype diversity in both parasites compared with drug resistance studies in other eukaryotic systems. Our analysis suggests a minimum of four independent origins of resistance mutations on just seven farms for H. contortus, and even more for T. circumincta. Both hard and soft selective sweeps have occurred with striking differences between individual farms. The sweeps are generally softer for T. circumcincta than H. contortus, consistent with its higher level of genetic diversity and consequent greater availability of new mutations. We propose a model in which multiple independent resistance mutations recurrently arise and spread by migration to explain the widespread occurrence of resistance in these parasites. Finally, in spite of the complex haplotypic diversity, we show that selection can be detected at the target locus using simple measures of genetic diversity and departures from neutrality. This work has important implications for the application of genome-wide approaches to identify new anthelmintic resistance loci and the likelihood of anthelmintic resistance emerging as selection pressure is increased in human soil-transmitted nematodes by community wide treatment programs
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Stress relief cracking in creep resisting low alloy ferritic steels.
Early investigations of the phenomenon of Stress Relief Cracking in low alloy steels suggested that the observed failure
along prior austenite grain boundaries was in large part promoted
by the relative strengthening of the grains with respect to the
grain boundaries, during the stress relieving heat treatment. In
this respect, it was felt that certain Cr-Mo-V steels containing
vanadium carbide should be particularly susceptible to this mode
of failure, since V4 C3 is well known to confer very good creep
strengthening in these low alloy steels. As a result of this
work, it has been established that the above view is both inaccurate
and misleading. Most of the experiments were performed
on two samples of commercially produced 1/2Cr 1/2Mo 1/2V steel. One of
these samples had proved to be susceptible to stress relief cracking
during fabrication. Detailed observations of the austenitic
grain growth and secondary hardening response of the two samples
are described. The results facilitated the design of a series of
high temperature hardness and tensile tests in which the separate
effects of grain strengthening and grain size in promoting high
temperature intergranular failure could be identified. In particular,
it is observed that although both steels exhibit very
similar strength characteristics, the effect of grain size in promoting
low ductility in association with intergranular failure is
more marked in one steel than in the other. The steel in which a
marked tendency towards stress relief cracking had been observed
is seen to show low ductilities at high temperatures even in fine
grain size specimens ; suggesting that the state of the boundaries,
independent of the strengthening effect, is an important factor in
promoting high temperature intergranular failure. By using an anisothermal
stress relaxation testing procedure, it was possible to
identify precisely the conditions of stress,temperature and microstructure
under which stress relief cracking occurs. In particular,
it was observed that the susceptible sample failed by nucleation
controlled intergranular cavitation in association with a
particular stress/strain-rate/temperature regime where the deformation
process is rate controlled by the diffusion of carbon.
Further experiments described in the latter part of the thesis
examine the effect of purity in promoting intergranular failure
both at low and high temperatures. The results suggest that the
presence of impurities like phosphorus, which are known to segregate
to prior austenite grain boundaries, may act to allow easier
nucleation and growth of cavities during failure by inter granular
cavitation. The conclusions of the thesis outline the mechanism
of stress relief cracking and make discussion in terms of current
theories of intergranular failure at high temperatures. Recommendations
are made concerning both the assessment of susceptibility
of steels to this mode of failure, as well as the adoption of safer
stress relief procedures
The impact of the Consumer Protection Act, 2008 on the accomodation segment of the tourism industry
The tourism industry is critically important for the economic well-being of South Africa. This realisation elicited a greater focus on the industry, including greater government regulation thereof. Although the concept of a tourist (consumer of tourism services) will not readily conjure up someone in need of protection, tourists are often exposed to exploitation through unfair business practices. Tourists, by definition, are outside their normal places of residence and often strangers to the environment within which they find themselves. For the important tourism industry to achieve its economic potential the protection of the tourist must be paramount. The introduction of the Consumer Protection Act, 2008 in 2010 was heralded as a new dawn for consumers. The CPA provides consumers, including domestic and foreign tourists, with extensive consumer rights. As the CPA is the first comprehensive legislation aimed at consumer protection the impact of the Act is far from known. The CPA caused considerable uncertainty in the tourism industry establishing a clear need to determine its impact on the segments of the industry. This study focuses on the accommodation segment. The aim of the study therefore is to ascertain the impact of selected consumer rights on the accommodation segment of the tourism industry. An overview of the tourism industry reveals that tourists are becoming more experienced, demanding and discerning. The regulation of the industry is explained. Particularly relevant are latest developments in South Africa, particularly the Draft Tourism Bill, 2011 and the National Tourism Sector Strategy. The consumer protection regime applicable prior to the coming into effect of the CPA was characterised more by ad hoc legislative arrangements than any systematic programme of consumer protection. Consumers were reliant on the common law. However, as part of a larger scheme to improve the socio-economic well-being of the people of South Africa, the government introduced a number of statutes including the CPA. The CPA introduced wide-ranging rights for the protection of consumers and mechanisms to provide effective redress. Selected consumer rights are critically analysed to assess the impact of these rights on the accommodation segment. These include the consumerâs right to equality in the market place; the right to privacy; the right to cancel advance bookings; the right to documentation in plain language; the right to quality service; and the right that a supplier having possession of the property of guest must account for such property. Another important aspect relates to the use of exemption provisions. The use of exemption provisions by suppliers is severely curtailed by the CPA. The use of prepaid vouchers, trade coupons and similar promotions, and customer loyalty programmes are also considered and the rights and obligations for consumers and suppliers respectively are elucidated. Many of the rights considered will have a significant impact on accommodation establishments. Elsewhere the impact may not appear to be as significant as the CPA is merely codifying an existing right or remedy. However, codifying the right, providing examples of the conduct prohibited and providing enforcement mechanisms will increase the efficacy of these rights
The impact of the Consumer Protection Act, 2008 on the accomodation segment of the tourism industry
The tourism industry is critically important for the economic well-being of South Africa. This realisation elicited a greater focus on the industry, including greater government regulation thereof. Although the concept of a tourist (consumer of tourism services) will not readily conjure up someone in need of protection, tourists are often exposed to exploitation through unfair business practices. Tourists, by definition, are outside their normal places of residence and often strangers to the environment within which they find themselves. For the important tourism industry to achieve its economic potential the protection of the tourist must be paramount. The introduction of the Consumer Protection Act, 2008 in 2010 was heralded as a new dawn for consumers. The CPA provides consumers, including domestic and foreign tourists, with extensive consumer rights. As the CPA is the first comprehensive legislation aimed at consumer protection the impact of the Act is far from known. The CPA caused considerable uncertainty in the tourism industry establishing a clear need to determine its impact on the segments of the industry. This study focuses on the accommodation segment. The aim of the study therefore is to ascertain the impact of selected consumer rights on the accommodation segment of the tourism industry. An overview of the tourism industry reveals that tourists are becoming more experienced, demanding and discerning. The regulation of the industry is explained. Particularly relevant are latest developments in South Africa, particularly the Draft Tourism Bill, 2011 and the National Tourism Sector Strategy. The consumer protection regime applicable prior to the coming into effect of the CPA was characterised more by ad hoc legislative arrangements than any systematic programme of consumer protection. Consumers were reliant on the common law. However, as part of a larger scheme to improve the socio-economic well-being of the people of South Africa, the government introduced a number of statutes including the CPA. The CPA introduced wide-ranging rights for the protection of consumers and mechanisms to provide effective redress. Selected consumer rights are critically analysed to assess the impact of these rights on the accommodation segment. These include the consumerâs right to equality in the market place; the right to privacy; the right to cancel advance bookings; the right to documentation in plain language; the right to quality service; and the right that a supplier having possession of the property of guest must account for such property. Another important aspect relates to the use of exemption provisions. The use of exemption provisions by suppliers is severely curtailed by the CPA. The use of prepaid vouchers, trade coupons and similar promotions, and customer loyalty programmes are also considered and the rights and obligations for consumers and suppliers respectively are elucidated. Many of the rights considered will have a significant impact on accommodation establishments. Elsewhere the impact may not appear to be as significant as the CPA is merely codifying an existing right or remedy. However, codifying the right, providing examples of the conduct prohibited and providing enforcement mechanisms will increase the efficacy of these rights
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