1,700 research outputs found
Building addiction recovery capital through online participation in a recovery community
The study examines how online participation in a recovery community contributes to personal journeys to addiction recovery. We investigate whether recovery capital building - as indicated by increased levels and quality of online social interactions - and markers of positive identity development predict retention in a recovery program designed around fostering community involvement for early stage recovery addicts. We predicted that high levels and quality of online participation on the group's Facebook page and positive identity development predict retention in the program. To map how participants interact online we conducted social network analysis (SNA) based on naturally occurring online data on the Facebook page of a recovery community. We used computerised linguistic analysis to conduct a sentiment analysis of the textual data (capturing social identity markers). We used linear regression analysis to test whether our indicators of recovery capital predict program retention. To illustrate our findings in the context of the recovery community, we also present case studies of two key participants who moved from the periphery to the centre of the social network. By conducting in-depth interviews with these participants we were able to explore personal experiences of social media usage in the context of their recovery journeys for group members who have undergone some of the most significant changes since joining the community. We found that retention in the program was determined by a) the number of comment 'likes' and 'all likes' received on the Facebook page; b) position in the social network (degree of centrality); and c) linguistic content around group identity and achievement. In conclusion, positive online interactions between members of recovery communities support the recovery process through helping participants to develop recovery capital that binds them to groups supportive of positive change
The properties of the star-forming interstellar medium at z=0.84-2.23 from HiZELS: mapping the internal dynamics and metallicity gradients in high-redshift disc galaxies
We present adaptive optics assisted, spatially resolved spectroscopy of a sample of nine H�-selected galaxies at z =0.84–2.23 drawn from the HiZELS narrow-band survey.
These galaxies have star-formation rates of 1–27M⊙ yr−1 and are therefore representative of the typical high-redshift star-forming population. Our �kpc-scale resolution
observations show that approximately half of the sample have dynamics suggesting that the ionised gas is in large, rotating disks. We model their velocity fields to infer
the inclination-corrected, asymptotic rotational velocities.We use the absolute B-band magnitudes and stellar masses to investigate the evolution of the B-band and stellar mass Tully-Fisher relationships. By combining our sample with a number of similar measurements from the literature, we show that, at fixed circular velocity, the stellar mass of star-forming galaxies has increased by a factor 2.5 between z =2 and z =0, whilst the rest-frame B-band luminosity has decreased by a factor �6 over the same
period. Together, these demonstrate a change in mass-to-light ratio in the B-band of �(M/ LB) / (M/ LB)z=0 �3.5 between z =1.5 and z =0, with most of the evolution occuring below z =1. We also use the spatial variation of [Nii] /H� to show that the metallicity of the ionised gas in these galaxies declines monotonically with galactocentric radius, with an average �log(O/H) /�R=−0.027±0.005 dex kpc−1. This gradient is consistent with predictions for high-redshift disk galaxies from cosmologically based hydrodynamic simulations.
Key words: galaxies: evolution – galaxies: formation – galaxies: high-redshif
Recognizing Speech in a Novel Accent: The Motor Theory of Speech Perception Reframed
The motor theory of speech perception holds that we perceive the speech of
another in terms of a motor representation of that speech. However, when we
have learned to recognize a foreign accent, it seems plausible that recognition
of a word rarely involves reconstruction of the speech gestures of the speaker
rather than the listener. To better assess the motor theory and this
observation, we proceed in three stages. Part 1 places the motor theory of
speech perception in a larger framework based on our earlier models of the
adaptive formation of mirror neurons for grasping, and for viewing extensions
of that mirror system as part of a larger system for neuro-linguistic
processing, augmented by the present consideration of recognizing speech in a
novel accent. Part 2 then offers a novel computational model of how a listener
comes to understand the speech of someone speaking the listener's native
language with a foreign accent. The core tenet of the model is that the
listener uses hypotheses about the word the speaker is currently uttering to
update probabilities linking the sound produced by the speaker to phonemes in
the native language repertoire of the listener. This, on average, improves the
recognition of later words. This model is neutral regarding the nature of the
representations it uses (motor vs. auditory). It serve as a reference point for
the discussion in Part 3, which proposes a dual-stream neuro-linguistic
architecture to revisits claims for and against the motor theory of speech
perception and the relevance of mirror neurons, and extracts some implications
for the reframing of the motor theory
Necessary and sufficient conditions of solution uniqueness in minimization
This paper shows that the solutions to various convex minimization
problems are \emph{unique} if and only if a common set of conditions are
satisfied. This result applies broadly to the basis pursuit model, basis
pursuit denoising model, Lasso model, as well as other models that
either minimize or impose the constraint , where
is a strictly convex function. For these models, this paper proves that,
given a solution and defining I=\supp(x^*) and s=\sign(x^*_I),
is the unique solution if and only if has full column rank and there
exists such that and for . This
condition is previously known to be sufficient for the basis pursuit model to
have a unique solution supported on . Indeed, it is also necessary, and
applies to a variety of other models. The paper also discusses ways to
recognize unique solutions and verify the uniqueness conditions numerically.Comment: 6 pages; revised version; submitte
Over 1200 drugs-related deaths and 190,000 opiate-user-years of follow-up : relative risks by sex and age-group
Heroin users/injectors' risk of drugs-related death by sex and current age is weakly estimated both in individual cohorts of under 1000 clients, 5000 person-years or 50 drugs-related deaths and when using cross-sectional data. A workshop in Cambridge analysed six cohorts who were recruited according to a common European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) protocol from drug treatment agencies in Barcelona, Denmark, Dublin, Lisbon, Rome and Vienna in the 1990s; and, as external reference, opiate-user arrestees in France and hepatitis C diagnosed ever-injectors in Scotland in 1993-2001, both followed by database linkage to December 2001. EMCDDA cohorts recorded approximately equal numbers of drugs-related deaths (864) and deaths from other non-HIV causes (865) during 106,152 person-years of follow-up. External cohorts contributed 376 drugs-related deaths (Scotland 195, France 181) and 418 deaths from non-HIV causes (Scotland 221, France 197) during 86,417 person-years of follow-up (Scotland 22,670, France 63,747). EMCDDA cohorts reported 707 drugs-related deaths in 81,367 man-years {8.7 per 1000 person-years, 95% CI: 8.1 to 9.4} but only 157 in 24,785 person-years for females {6.3 per 1000 person-years, 95% CI: 5.4 to 7.4}. Except in external cohorts, relative risks by current age-group were not particularly strong, and more modest in Poisson regression than in cross-sectional analyses: relative risk was 1.2 (95% CI: 1.0-1.4) for 35-44 year olds compared to 15-24 year 3 olds, but 1.4 for males (95%CI: 1.2-1.6), and dramatically lower at 0.44 after the first year of follow-up (95% CI: 0.37-0.52)
Automata for true concurrency properties
We present an automata-theoretic framework for the model checking of true concurrency properties. These are specified in a fixpoint logic, corresponding to history-preserving bisimilarity, capable of describing events in computations and their dependencies. The models of the logic are event structures or any formalism which can be given a causal semantics, like Petri nets. Given a formula and an event structure satisfying suitable regularity conditions we show how to construct a parity tree automaton whose language is non-empty if and only if the event structure satisfies the formula. The automaton, due to the nature of event structure models, is usually infinite. We discuss how it can be quotiented to an equivalent finite automaton, where emptiness can be checked effectively. In order to show the applicability of the approach, we discuss how it instantiates to finite safe Petri nets. As a proof of concept we provide a model checking tool implementing the technique
Group identification and addictive health behaviours in adolescents
As contemporary approaches to addiction treatment are evolving from models predominantly focused on acute bio-psychosocial stabilisation to models similar to managing chronic diseases such as diabetes and high blood pressure (White, 2009), the importance of communities of support becomes more central. The role of social support groups in recovery from addiction (Best et al., 2016), and other health conditions (Jetten, Haslam, & Haslam, 2012) has long been recognised and extensively researched. There has been a move from models predicated on an ‘individual struggle’ to a shared recovery process, that is, from an individual-focused approach to change to more socially oriented alternatives, not only regarding treat - ment per se, but also in how support for recovery is conceptualised (Beckwith, Bliuc, & Best, 2016; White, 1998). Recent definitions of recovery from addiction characterise recovery as a “process of change through which individuals improve their health and wellness, live self-directed lives, and strive to reach their full potential” (Substance Abuse and Mental Health Services Administration, 2012). SAMHSA’s working definition of recovery encompasses four dimensions necessary to support recovery – health, home, purpose and community – incorporating the recognition that, during this process, social support is paramount (Betty Ford Institute, 2007)
Visual Dependency and Dizziness after Vestibular Neuritis
Symptomatic recovery after acute vestibular neuritis (VN) is variable, with around 50% of patients reporting long term vestibular symptoms; hence, it is essential to identify factors related to poor clinical outcome. Here we investigated whether excessive reliance on visual input for spatial orientation (visual dependence) was associated with long term vestibular symptoms following acute VN. Twenty-eight patients with VN and 25 normal control subjects were included. Patients were enrolled at least 6 months after acute illness. Recovery status was not a criterion for study entry, allowing recruitment of patients with a full range of persistent symptoms. We measured visual dependence with a laptop-based Rod-and-Disk Test and severity of symptoms with the Dizziness Handicap Inventory (DHI). The third of patients showing the worst clinical outcomes (mean DHI score 36–80) had significantly greater visual dependence than normal subjects (6.35° error vs. 3.39° respectively, p = 0.03). Asymptomatic patients and those with minor residual symptoms did not differ from controls. Visual dependence was associated with high levels of persistent vestibular symptoms after acute VN. Over-reliance on visual information for spatial orientation is one characteristic of poorly recovered vestibular neuritis patients. The finding may be clinically useful given that visual dependence may be modified through rehabilitation desensitization techniques
Extragalactic Radio Continuum Surveys and the Transformation of Radio Astronomy
Next-generation radio surveys are about to transform radio astronomy by
discovering and studying tens of millions of previously unknown radio sources.
These surveys will provide new insights to understand the evolution of
galaxies, measuring the evolution of the cosmic star formation rate, and
rivalling traditional techniques in the measurement of fundamental cosmological
parameters. By observing a new volume of observational parameter space, they
are also likely to discover unexpected new phenomena. This review traces the
evolution of extragalactic radio continuum surveys from the earliest days of
radio astronomy to the present, and identifies the challenges that must be
overcome to achieve this transformational change.Comment: To be published in Nature Astronomy 18 Sept 201
Safety of low-carbohydrate diets
Low-carbohydrate diets have re-emerged into the public spotlight and are enjoying a high degree of popularity as people search for a solution to the population\u27s ever-expanding waistline. The current evidence though indicates that low-carbohydrate diets present no significant advantage over more traditional energy-restricted diets on long-term weight loss and maintenance. Furthermore, a higher rate of adverse side-effects can be attributed to low-carbohydrate dieting approaches. Short-term efficacy of low-carbohydrate diets has been demonstrated for some lipid parameters of cardiovascular risk and measures of glucose control and insulin sensitivity, but no studies have ascertained if these effects represent a change in primary outcome measures. Low-carbohydrate diets are likely effective and not harmful in the short term and may have therapeutic benefits for weight-related chronic diseases although weight loss on such a program should be undertaken under medical supervision. While new commercial incarnations of the low-carbohydrate diet are now addressing overall dietary adequacy by encouraging plenty of high-fibre vegetables, fruit, low-glycaemic-index carbohydrates and healthier fat sources, this is not the message that reaches the entire public nor is it the type of diet adopted by many people outside of the world of a well-designed clinical trial. Health effects of long-term ad hoc restriction of inherently beneficial food groups without a concomitant reduction in body weight remains unanswered.<br /
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