5,901 research outputs found
An ultra scale-down analysis of the recovery by dead-end centrifugation of human cells for therapy.
An ultra scale-down method is described to determine the response of cells to recovery by dead-end (batch) centrifugation under commercially defined manufacturing conditions. The key variables studied are the cell suspension hold time prior to centrifugation, the relative centrifugal force (RCF), time of centrifugation, cell pellet resuspension velocities, and number of resuspension passes. The cell critical quality attributes studied are the cell membrane integrity and the presence of selected surface markers. Greater hold times and higher RCF values for longer spin times all led to the increased loss of cell membrane integrity. However, this loss was found to occur during intense cell resuspension rather than the preceding centrifugation stage. Controlled resuspension at low stress conditions below a possible critical stress point led to essentially complete cell recovery even at conditions of extreme centrifugation (e.g., RCF of 10000 g for 30 mins) and long (~2 h) holding times before centrifugation. The susceptibility to cell loss during resuspension under conditions of high stress depended on cell type and the age of cells before centrifugation and the level of matrix crosslinking within the cell pellet as determined by the presence of detachment enzymes or possibly the nature of the resuspension medium. Changes in cell surface markers were significant in some cases but to a lower extent than loss of cell membrane integrity. Biotechnol. Bioeng. 2015;112: 997-1011. © 2014 Wiley Periodicals, Inc
Turds, traitors and tossers : the abuse of UK MPs via Twitter
There has been growing public attention around the abuse of MPs online including criminal convictions for violent threats, regular coverage of racist and misogynistic language directed at representatives. Yet, the extent of the problem and patterns of abuse remain relatively under-researched. So far, much of coverage of the problem is anecdotal or based on self-reporting from MPs. This research sets out to provide a more rigorous benchmark measure of abuse. It also examines targets and triggers for social media abuse – how far is abuse connected to contentious debates such as Brexit or targeted at specific groups of MPs (e.g. female representatives)? Our results indicate that whilst the overall volume of abuse appears low, social media abuse has become ubiquitous and is highly public. Furthermore, whilst some abuse is undoubtedly targeted and gendered, the biggest proportion of abuse follows a reactive response to political discussions and public interventions of MPs
Perinatal Gene Transfer to the Liver
The liver acts as a host to many functions hence raising the possibility that any one may be compromised by a single gene defect.
Inherited or de novo mutations in these genes may result in relatively mild diseases or be so devastating that death within the first
weeks or months of life is inevitable. Some diseases can be managed using conventional medicines whereas others are, as yet, untreatable.
In this review we consider the application of early intervention gene therapy in neonatal and fetal preclinical studies. We appraise
the tools of this technology, including lentivirus, adenovirus and adeno-associated virus (AAV)-based vectors. We highlight the application
of these for a range of diseases including hemophilia, urea cycle disorders such as ornithine transcarbamylase deficiency, organic
acidemias, lysosomal storage diseases including mucopolysaccharidoses, glycogen storage diseases and bile metabolism. We conclude by
assessing the advantages and disadvantages associated with fetal and neonatal liver gene transfer
Advances in applied zoo animal welfare science
Nonhuman animal welfare science is the scientific study of the welfare state of animals that attempts to make inferences about how animals feel from their behavior, endocrine function, and/or signs of physical health. These welfare measurements are applicable within zoos yet inherently more complex than in farms and laboratories. This complexity is due to the vast number of species housed, lack of fundamental biological information, and relatively lower sample sizes and levels of experimental control. This article summarizes the invited presentations on the topic of "Advances in Applied Animal Welfare Science," given at the Fourth Global Animal Welfare Congress held jointly by the Detroit Zoological Society and the World Association of Zoos and Aquariums in 2017. The article focuses on current trends in research on zoo animal welfare under the following themes: (a) human–animal interactions and relationships, (b) anticipatory behavior, (c) cognitive enrichment, (d) behavioral biology, and (e) reproductive and population management. It highlights areas in which further advancements in zoo animal welfare science are needed and the challenges that may be faced in doing so
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Behaviour and enclosure use of captive parma wallabies (Macropus parma): an assessment of compatibility within a mixed-species exhibit
Many zoos choose to house parma wallabies (Macropus parma) in mixed-species exhibits and a successful combination of species can provide a source of enrichment. However, there are potential health and welfare concerns, so it is important to consider species compatibility. This study investigates the effects of mixed-species housing on the parma wallaby. Parma wallabies at Dudley Zoological Gardens were observed for nine days in two different housing systems: mixed species (MS), with Patagonian mara (Dolichotis patagonum), and single species (SS). Scan sampling of all individuals, across a range of behaviours, was carried out for 90 minutes across the day. Differences in foraging behaviour were observed, with wallabies housed in the MS exhibit foraging significantly less than the SS group (W27=899.0, P<0.01). Wallabies in the MS enclosure performed a novel behaviour, agonistic directional urination that was not observed in the SS group. Enclosure use was analysed using a Spread of Participation Index (SPI); values revealed MS wallabies utilised less of their enclosure, with a notable preference for areas not frequented by the mara (W27=899.0, P<0.05). The results suggest that the MS wallabies are affected by the presence of the mara, both behaviourally and in enclosure use, which could be indicative of a negative welfare state. This study provides evidence of species incompatibility, a potential issue for the welfare of captive parma wallabies and the successful maintenance of this species in captivity. Careful and continual monitoring of species within mixed-species enclosures is recommended
Core–shell grain structures and ferroelectric properties of Na0.5K0.5NbO3–LiTaO3–BiScO3 piezoelectric ceramics
Legislation arising from health and environmental concerns has intensified research into finding suitable alternatives to lead-based piezoceramics. Recently, solid solutions based on sodium potassium niobate (K,Na)NbO3 (KNN) have become one of the globally-important lead-free counterparts, due to their favourable dielectric and piezoelectric properties. This data article provides information on the ferroelectric properties and core–shell grain structures for the system, (1−y)[(1−x)Na0.5K0.5NbO3 – xLiTaO3] – yBiScO3 (x=0–0.1, y=0.02, abbreviated as KNN–xLT–2BS). We show elemental analysis with aid of TEM spot-EDX to identify three-type grain-types in the KNN–LT–BS ternary system. Melting behaviour has been assessed using a tube furnace with build-in camera. Details for the ferroelectric properties and core–shell chemical segregation are illustrated
A tale of three tribes : UK MPs, Twitter and the EU Referendum
This paper examines the structure of Twitter communication networks between MPs during the 2016 EU Referendum campaign. In particular, the research examines the impact of Twitter in two dimensions: (1) how far social media might facilitate inter-party linkages thus eroding traditional partisan relations between MPs? This was given added potential by the supposedly cross-party nature of the Referendum campaign and, therefore, we specifically examined the collective communicative networks that formed around Leave and Remain amongst MPs; (2) Given the potential of social media to provide a platform for individual politicians to personalize campaigns, we asked how far social media might disrupt traditional formal intra-party hierarchies? Did, for example, backbench or relatively unknown figures come to the fore in the EU debate? Our results indicate that whilst there existed a high degree of partisanship, interestingly, Remainer MPs tended to adhere to party networks resulting in a divided remain network. By contrast, the Leave network was more unified but also more porous. Within the networks themselves, the centrality of individual MPs did not always reflect their formal status
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