12,195 research outputs found
Laser beam pointing tests
Laser beam pointing tests for lunar communication and rangefinding and tracking using Surveyor 7 vidicon camer
Hepatic microRNA profiles offer predictive and mechanistic insights after exposure to genotoxic and epigenetic hepatocarcinogens.
In recent years, accumulating evidence supports the importance of microRNAs in liver physiology and disease; however, few studies have examined the involvement of these noncoding genes in chemical hepatocarcinogenesis. Here, we examined the liver microRNA profile of male Fischer rats exposed through their diet to genotoxic (2-acetylaminofluorene) and epigenetic (phenobarbital, diethylhexylphthalate, methapyrilene HCL, monuron, and chlorendic acid) chemical hepatocarcinogens, as well as to non-hepatocarcinogenic treatments (benzophenone, and diethylthiourea) for 3 months. The effects of these treatments on liver pathology, plasma clinical parameters, and liver mRNAs were also determined. All hepatocarcinogens affected the expression of liver mRNAs, while the hepatic microRNA profiles were associated with the mode of action of the chemical treatments and corresponded to chemical carcinogenicity. The three nuclear receptor-activating chemicals (phenobarbital, benzophenone, and diethylhexylphthalate) were characterized by the highly correlated induction of the miR-200a/200b/429, which is involved in protecting the epithelial status of cells and of the miR-96/182 clusters. The four non-nuclear receptor-activating hepatocarcinogens were characterized by the early, persistent induction of miR-34, which was associated with DNA damage and oxidative stress in vivo and in vitro. Repression of this microRNA in a hepatoma cell line led to increased cell growth; thus, miR-34a could act to block abnormal cell proliferation in cells exposed to DNA damage or oxidative stress. This study supports the proposal that hepatic microRNA profiles could assist in the earlier evaluation and identification of hepatocarcinogens, especially those acting by epigenetic mechanisms. © The Author 2012. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved
Time and dose-dependent effects of phenobarbital on the rat liver miRNAome.
In a previous study we had shown that treatment of male Fischer rats with exogenous chemicals for three months resulted in prominent, mode-of-action dependent effects on liver microRNA (miRNA) (Koufaris et al., 2012). Here we investigated how the effects of chemicals on liver miRNA in male Fischer rats relate to the length and dose of exposure to phenobarbital (PB), a drug with multiple established hepatic effects. Importantly, although acute PB treatment (1-7 days) had significant effects on liver mRNA and the expected effects on the liver phenotype (transient hyperplasia, hepatomegaly, cytochrome P450 induction), limited effects on liver miRNA were observed. However, at 14 days of PB treatment clear dose-dependent effects on miRNA were observed. The main effect of PB treatment from days 1 to 90 on liver miRNA was found to be the persistent, progressive, and highly correlated induction of the miR-200a/200b/429 and miR-96/182 clusters, occurring after the termination of the xenobiotic-induced transient hyperplasia. Moreover, in agreement with their reported functions in the literature we found associations between perturbations of miR-29b and miR-200a/200b by PB with global DNA methylation and zeb1/zeb2 proteins respectively. Our data suggest that miRNA are unlikely to play an important role in the acute responses of the adult rodent liver to PB treatment. However, the miRNA responses to longer PB exposures suggest a potential role for maintaining liver homeostasis in response to sub-chronic and chronic xenobiotic-induced perturbations. Similar studies for more chemicals are needed to clarify whether the temporal and dose pattern of miRNA-toxicant interaction identified here for PB are widely applicable to other xenobiotics. © 2013 Elsevier Ireland Ltd
Bringing genetics into primary care: findings from a national evaluation of pilots in England
Objectives: Developments in genetic knowledge and clinical applications are seen as rendering traditional modes of organizing genetics provision increasingly inappropriate. In common with a number of developed world countries the UK has sought to increase the role of primary care in delivering such services. However, efforts to reconfigure service delivery face multiple challenges associated with divergent policy objectives, organizational boundaries and professional cultures. This paper presents findings from an evaluation of an English initiative to integrate genetics into 'mainstream' clinical provision in the National Health Service. Methods: Qualitative research in 11 case-study sites focusing on attempts by pilots funded by the initiative to embed knowledge and provision within primary care illustrating barriers faced and the ways in which these were surmounted. Results: Lack of intrinsic interest in clinical genetics among primary care staff was compounded by national targets that focused their attention elsewhere and by service structures that rendered genetics a peripheral concern demanding minimal engagement. Established divisions between the commissioning of mainstream and specialist services, along with the pressures of shorter-term targets, impeded ongoing funding. Conclusions: More wide-ranging policy and organizational support is required if the aim of entrenching genetics knowledge and practice across the Health Service is to be realized
Mindfulness mirror
This paper explores the use of an interactive Genetic Algorithm for creating a piece of visual art intended to assist in promoting the state of mindfulness. This is determined by a Bluetooth gaming electroencephalography (EEG) headset as the fitness function. The visual display consisted of an infinity mirror with over two hundred Neopixels with fade times and colour of zones controlled by two Ardu-inos running the software. Whilst we have observed some convergence of solu-tions, the results and user observations raised some interesting questions about how this strategy might be improved
A survey of the benefits and issues arising from the deployment of physical artefacts in computer science teaching
This paper describes the introduction of the use of physical artefacts in the teaching of the curriculum in the Department of Computer Science at Middlesex University. The rationale for the change is discussed, together with a description of the various technologies and the areas in which they were deployed. We conclude with a discussion of the outcomes of the work and the conclusions reached, prime amongst which are that the policy has been successful in motivating and engaging students, with a resultant improvement in student progression. In addition to their value in the taught part of the curriculum, these technologies have enabled students to become involved in real-world projects, interacting with external organizations and producing products of value in diverse areas such as the arts and assistive technologies
Smart feedback and the challenges of virtualisation
The use of audio feedback is becoming more prevalent and it would be possible to use avatars for this purpose. When audio feedback is recorded by a human tutor, the recording contains not only the text of the feedback, but also additional information associated with the intonation and manner of delivery of the voice. Experiments were conducted to investigate student’s responses to the use of audio in comparison with other forms of feedback. Students were generally positive about audio feedback; results also indicated that the conveyed emotion or intent is significant and that it is perceived by the student as an important part of the feedback. We also explore this in the context of strategies for the deployment of virtual agents in the provision of feedback
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