299 research outputs found
The amino acid sensitive TOR pathway from yeast to mammals
AbstractThe target of rapamycin (TOR) is an ancient effector of cell growth that integrates signals from growth factors and nutrients. Two downstream effectors of mammalian TOR, the translational components S6K1 and 4EBP1, are commonly used as reporters of mTOR activity. The conical signaling cascade initiated by growth factors is mediated by PI3K, PKB, TSC1/2 and Rheb. However, the process through which nutrients, i.e., amino acids, activate mTOR remains largely unknown. Evidence exists for both an intracellular and/or a membrane bound sensor for amino acid mediated mTOR activation. Research in eukaryotic models, has implicated amino acid transporters as nutrient sensors. This review describes recent advances in nutrient signaling that impinge on mTOR and its targets including hVps34, class III PI3K, a transducer of nutrient availability to mTOR
Towards a quantitative indicator of feather disruption following the cleansing of oiled birds
The measurement of flow velocity distribution
Includes bibliography.A method for the improvement of the range and accuracy achieved by the cross-correlation flowmeter is investigated. The principles of the flowmeter operation and fundamental digital signal processing techniques are reviewed. The process of the Fourier transform deconvolution is investigated. Computer simulation of the flow system is described and is shown to require impractical amounts of computer time to achieve the necessary averaging times. Consequently, correlation and velocity profile measurements are made from an experimental flow rig. A waveform analysis program is used to analyse these measurements. The Fourier transform deconvolution is shown in this case to have poor noise immunity. For this reason, an alternative method of Bayesian deconvolution is investigated. The correlation functions measured from the experimental flow rig are deconvolved using the Bayesian deconvolution algorithm. The resulting transit time distribution is shown to converge to the transit time distribution obtained from the velocity profile measurements. From an analysis of the flow signals the velocity distribution of the flow may thus be found
Motor Neurone Disease (MND) and Amyotrophic Lateral Sclerosis (ALS): Social Media Communication on Selected #MND and #ALS Tagged Tweets
In March-April 2016, 3288 original tweets tagged with #MND #ALS and other minor related tags (e.g., #cureALS #cureMND) were analysed using mixed quantitative and qualitative methods on tweet data and content. In this paper we outline the technical methods used in gathering and selecting relevant tweets for analysis, and present the results including inductive coding of content themes. The findings will inform (a) future social media research in relation to MND/ALS, (b) improved supports for people with MND/ALS and their families to use Twitter for information exchange, advocacy, and as a non-verbal form of communication, and (c) knowledge for MND/ALS service providers and philanthropic organisations on ways to engage with adults with MND/ALS in Twitter
Are poor set-shifting and central coherence associated with everyday function in anorexia nervosa? A systematic review
Background: There is increasing interest in associations between cognitive impairments and clinical symptoms in Anorexia Nervosa (AN), however, the relationship with everyday function is unclear. The current review synthesizes existing data regarding associations between scores on tests of set-shifting and central coherence and functional outcome measures for individuals with AN. Method: A systematic electronic database search yielded 13 studies which included participants with current or lifetime AN where scores on a neuropsychological test of set-shifting or central coherence were directly or indirectly compared to a functional outcome measure. Results: Associations between set-shifting and central coherence performance measures and functional outcomes were limited in number and noted only in adult or mixed-age cohorts. Associations were noted at subscale level, suggesting they are specific in nature. In younger cohorts, assessments of executive functioning in everyday life appear sensitive to cognitive-behavioral flexibility issues. Conclusions: Associations between cognitive performance and functional outcome have not been as systematically assessed in AN as in other psychiatric disorders. Key factors to address in future research include: (a) the use of function measures which are sensitive to both the level of impairment, and specific rather than general impairments (b) the ecological validity of measures, (c) the task impurity problem, especially in regard to cognitive flexibility assessment, and (d) the need to measure both cognitive deficits and strengths, because tests of specific cognitive processes may underestimate the ability to function in daily life due to compensatory strategies
Secondary ferrimagnetic minerals in Welsh soils: a comparison of mineral magnetic detection methods and implications for mineral formation
Review of the literature on the use of social media by people with traumatic brain injury (TBI)
Purpose: To review the literature relating to use of social media by people with a traumatic brain injury (TBI), specifically its use for social engagement, information exchange or rehabilitation. Method: A systematic review with a qualitative meta-synthesis of content themes was conducted. In June 2014, 10 databases were searched for relevant, peer-reviewed research studies in English that related to both TBI and social media. Results: Sixteen studies met the inclusion criteria, with Facebook™ and Twitter™ being the most common social media represented in the included studies. Content analysis identified three major categories of meaning in relation to social media and TBI: (1) risks and benefits; (2) barriers and facilitators; and (3) purposes of use of social media. A greater emphasis was evident regarding potential risks and apparent barriers to social media use, with little focus on facilitators of successful use by people with TBI. Conclusions: Research to date reveals a range of benefits to the use of social media by people with TBI however there is little empirical research investigating its use. Further research focusing on ways to remove the barriers and increase facilitators for the use of social media by people with TBI is needed. Implications for Rehabilitation: Communication disabilities following traumatic brain injury (TBI) can be wide-ranging in scope and social isolation with loss of friendships after TBI is common. For many people, social media is rapidly becoming a usual part of everyday communication and its use has the potential to increase communication and social participation for people with TBI.There is emerging evidence and commentary regarding the perceived benefits and risks, barriers and facilitators and purposes of use of social media within the TBI population.Risks associated with using social media, and low accessibility of social media sites, form barriers to its use. Facilitators for social media use in people with TBI include training the person with TBI and their communication partners in ways to enjoy and use social media safely.There is minimal rigorous evaluation of social media use by people with TBI and scant information regarding social media use by people with communication disabilities after TBI. Further investigation is needed into the potential benefits of social media use on communication, social participation and social support with the aim of reducing social isolation in people with TBI
“We definitely need an audience”: experiences of Twitter, Twitter networks and tweet content in adults with severe communication disabilities who use augmentative and alternative communication (AAC)
Purpose: The aim of this study was to investigate the Twitter experiences of adults with severe communication disabilities who use augmentative and alternative communication (AAC) to inform Twitter training and further research on the use of Twitter in populations with communication disabilities. Method: This mixed methods research included five adults with severe communication disabilities who use AAC. It combined (a) quantitative analysis of Twitter networks and (b) manual coding of tweets with (c) narrative interviews with participants on their Twitter experiences and results. Results: The five participants who used AAC and Twitter were diverse in their patterns and experiences of using Twitter. Twitter networks reflected interaction with a close-knit network of people rather than with the broader publics on Twitter. Conversational, Broadcast and Pass Along tweets featured most prominently, with limited use of News or Social Presence tweets. Tweets appeared mostly within each participant's micro- or meso-structural layers of Twitter. Conclusions: People who use AAC report positive experiences in using Twitter. Obtaining help in Twitter, and engaging in hashtag communities facilitated higher frequency of tweets and establishment of Twitter networks. Results reflected an inter-connection of participant Twitter networks that might form part of a larger as yet unexplored emergent community of people who use AAC in Twitter.Implications for RehabilitationTwitter can be used as an important vehicle for conversation and a forum for people with communication disabilities to exchange information and participate socially in online communities.It is important that information and resources relating to the effective use of Twitter for a range of purposes are made available to people with communication disabilities who wish to take up or maintain use of Twitter.People with communication disabilities might benefit from support in using Twitter to meet their goals relating to participation in online forums and information exchange. Practitioners need to consider how their own social media skills might impact on service delivery and supporting these goals
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