2,340 research outputs found
Triplanar Model for the Gap and Penetration Depth in YBCO
YBaCuO_7 is a trilayer material with a unit cell consisting of a CuO_2
bilayer with a CuO plane of chains in between. Starting with a model of
isolated planes coupled through a transverse matrix element, we consider the
possibility of intra as well as interplane pairing within a nearly
antiferromagnetic Fermi liquid model. Solutions of a set of three coupled BCS
equations for the gap exhibit orthorhombic symmetry with s- as well as d-wave
contributions. The temperature dependence and a-b in plane anisotropy of the
resulting penetration depth is discussed and compared with experiment.Comment: To appear in Physical Review B1 01Mar97; 12 pages with 10 figures;
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Ethical standards for robotics: exploring post-automation potentials
This paper explores how explicitly ethical standards for robotics are peer-produced. It describes the motivations, organisation and practices of standardization contributed by a globally distributed community of experts. The research question asks what kind of rules for robots are being created through standardization and what are the motivational and organizational features of this knowledge production? In addressing this question, I reflect on how ethical principles are applied in practice within the field of autonomous and intelligent systems and what implications this may have for the governance of robotics innovation. The paper directly responds to the aims of the workshop by speculating on the potential for post-automation robotics innovation pathways that are not automatically determined, but arrived at by means of broad participation in governance decisions and innovation processes
Accountability and neglect in UK social care innovation
Accountability structures in social care are critical. They facilitate democratic decision-making, responsibility and the equitable distribution of benefits. This study examines how innovation and technology is implicated in such structures. In the UK, innovation and technology researchers have predominantly imagined care as service provision, with accountability structured through paternalistic and technocratic configurations of people, materials and knowledge. Aligning with incumbent policy and interests, these structures neglect significant groups of actors and issues, with implications for ongoing vulnerabilities in the sector. This study empirically identifies diverse possibilities for how innovation could reconfigure accountability structures in inclusive, participative and less neglectful ways
Lipase inhibition attenuates the acute inhibitory effects of oral fat on food intake in healthy subjects
The lipase inhibitor, orlistat, is used in the treatment of obesity and reduces fat absorption by about 30%. However, the mean weight loss induced by orlistat is less than expected for the degree of fat malabsorption. It was hypothesised that lipase inhibition with orlistat attenuates the suppressive effects of oral fat on subsequent energy intake in normal-weight subjects. Fourteen healthy, lean subjects (nine males, five females; aged 25 +/- 1.3 years) were studied twice, in a double-blind fashion. The subjects received a high-fat yoghurt 'preload' (males 400 g (2562 kJ); females 300 g (1923 kJ)), containing orlistat (120 mg) on one study day (and no orlistat on the other 'control' day), 30 min before ad libitum access to food and drinks; energy intake was assessed during the following 8 h. Blood samples were taken at regular intervals for the measurement of plasma cholecystokinin (CCK). Each subject performed a 3 d faecal fat collection following each study. Energy intake during the day was greater following orlistat (10,220 (SEM 928) kJ) v. control (9405 (SEM 824) kJ) (P=0.02). On both days plasma CCK increased (P<0.05) after the preload. Plasma CCK 20 min following ingestion of the preload was less after orlistat (4.1 (SEM 0.9) pmol/l) v. control (5.3 (SEM 0.9) pmol/l (P=0.028); however there was no difference in the area under the curve 0-510 min between the two study days. Fat excretion was greater following orlistat (1017 (SEM 168) kJ) v. control (484 (SEM 90) kJ) (P=0.004). In conclusion, in healthy, lean subjects the acute inhibitory effect of fat on subsequent energy intake is attenuated by orlistat and the increase in energy intake approximates the energy lost due to fat malabsorption.Deirdre OāDonovan, Christine Feinle-Bisset, Judith Wishart and Michael Horowit
AI ethics from the ground up: cultivating interdisciplinary capabilities (for care)
Interdisciplinary research has led to significant breakthroughs in the fields of AI, robotics and autonomous systems. Yet it has also been the basis of significant controversies. Cambridge Analytica and Facebook's amalgam of psychographics, data science and engineering at scale being perhaps the most infamous recent example. Despite continued promotion from research funders, it should be clear then that interdisciplinary research is not in itself an uncontested good. This presentation aims to explore the political and ethical dimensions of interdisciplinary research practices in the fields of AI, robotics and autonomous systems. Following a human capabilities approach and using mixed-methods, we locate and map a set of research capabilities valued by researchers at the Bristol Robotics Laboratory. This prompts a discussion on what it means to consider ethics of AI, not from a set of normative statements, but as practiced on the ground
They promised me robots
STS researchers like me have a thing about nosing around other peopleās labs. Ignore us, we say. Wonāt bother you. Weāre just here observing your routines, your cultures, your politics, and how you stir them into technology in the making. That was exactly my pitch to roboticists at BRL. They were taking technology from their lab and testing them in care homes amongst actual users. Or was that on actual users. Either way, I was here to find out the hows and whys of robotics testing in the wil
Optimisation of the production of cathepsin L1 from a recombinant saccharomyces cerevisiae
Cathepsin L1 is a cysteine protease that has been previously isolated and functionally expressed in Saccharomyces cerevisiae. It has the potential to be employed as a vaccine for liver-fluke disease in cattle and other ruminants. Production of this recombinant enzyme, which is secreted into the media from recombinant yeast, was studied initially in shake flask cultures and subsequently in 5L and 15L fermenters.
In early studies, low productivity and especially variations in Cathepsin L1 production was a significant problem. A standard operating protocol (SOP) has been designed to consistently supply an optimum inoculum for large-scale fermentations. This SOP which involved 'blending' colonies for inoculum cultures in conjunction with sub-culturing starter flasks for two successive cycles of 48 hours, proved to be the most successful for consistently high levels of enzyme production during the ensuing fermentation.
The pH and temperature optima are pH 6.5 and 30Ā°C respectively for culturing the recombinant yeast to produce both both high biomass levels and high enzyme activity. Addition of casamino acids to the selective media or replacing it with complex YEPD resulted in poor plasmid stability and low Cathepsin L1 production. By supplementing the selective media with extra yeast nitrogen base, using a glucose concentration of 20g/L, enzyme activity increased by 3-4 fold and much higher levels of plasmid stability than observed in non-selective media were sustained. Enzyme activity of 0.74 units/mL were obtained in supplemented media compared to 0.19 units/mL in selective media.
Investigations were performed on the constitutive behaviour of the ADH1 promoter, which controls the expression of Cathepsin L1 in this recombinant yeast strain. It revealed that enzyme production is repressed at high concentrations of glucose but gradually increases as glucose is utilised. Cathepsin L1 is still expressed during the ethanol consumption phase, albeit at a slower rate than during the latter stages of glucose consumption
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