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Emerging evidence suggests that sedentary behaviour, specifically time spent taking part in screen-based activities, such as watching television, may be associated with mental health outcomes in young people [1]. However, recent reviews have found limited and conflicting evidence for both anxiety and depression [2].
Objectives
The purpose of the study was to explore associations between screen time at age 16 years and anxiety and depression at 18.
Methods
Subjects (n = 1958) were from the Avon Longitudinal Study of Parents and Children (ALSPAC), a UK-based prospective cohort study. We assessed associations between screen time (measured via questionnaire at 16 years) and anxiety and depression (measured in a clinic at 18 years using the Revised Clinical Interview Schedule) using ordinal logistic regression, before and after adjustment for covariates (including sex, maternal education, family social class, parental conflict, bullying and maternal depression).
Results
After adjusting for potential confounders, we found no evidence for an association between screen time and anxiety (OR = 1.02; 95% CI 0.95–1.09). There was weak evidence that greater screen time was associated with a small increased risk of depression (OR = 1.05, 95% CI 0.98–1.13).
Conclusions
Our results suggest that young people who spend more time on screen-based activities may have a small increased risk of developing depression but not anxiety. Reducing youth screen time may lower the prevalence of depression. The study was limited by screen time being self-reported, a small sample size due to attrition and non-response, and the possibility of residual confounding. Reverse causation cannot be ruled out.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
Current approaches to assess violence risk in secure hospitals are resource intensive, limited by accuracy and authorship bias and may have reached a performance ceiling. This study seeks to develop scalable predictive models for violent offending following discharge from secure psychiatric hospitals.
Methods
We identified all patients discharged from secure hospitals in Sweden between January 1, 1992 and December 31, 2013. Using multiple Cox regression, pre-specified criminal, sociodemographic, and clinical risk factors were included in a model that was tested for discrimination and calibration in the prediction of violent crime at 12 and 24 months post-discharge. Risk cut-offs were pre-specified at 5% (low vs. medium) and 20% (medium vs. high).
Results
We identified 2248 patients with 2933 discharges into community settings. We developed a 12-item model with good measures of calibration and discrimination (area under the curve = 0.77 at 12 and 24 months). At 24 months post-discharge, using the 5% cut-off, sensitivity was 96% and specificity was 21%. Positive and negative predictive values were 19% and 97%, respectively. Using the 20% cut-off, sensitivity was 55%, specificity 83% and the positive and negative predictive values were 37% and 91%, respectively. The model was used to develop a free online tool (FoVOx).
Interpretation
We have developed a prediction score in a Swedish cohort of patients discharged from secure hospitals that can assist in clinical decision-making. Scalable predictive models for violence risk are possible in specific patient groups and can free up clinical time for treatment and management. Further evaluation in other countries is needed.
Funding
Wellcome Trust (202836/Z/16/Z) and the Swedish Research Council. The funding sources had no involvement in writing of the manuscript or decision to submit or in data collection, analysis or interpretation or any aspect pertinent to the study.
Detailed measurements of the altitudes of the shorelines of former ice-dammed lakes in Glen Roy and vicinity in the Scottish Highlands prove erroneous the conventional view that former shorelines in areas affected by glacio-isostatic uplift are uniformly tilted and/or gently warped. The measurements demonstrate differential uplift of blocks of the earth's crust. The surfaces of some blocks have no detectable tilt whereas others have gradients up to at least 4.6 m/km and are tilted in different directions. In three areas 0.7–2.0 km long, shorelines are distorted by crustal movements; all these areas have landslides attributed to earthquakes that accompanied the release of stress. In the area of greatest local distortion three shorelines rose about 3 m above their average altitudes for the immediately surrounding area, and a fault scarp was produced. Possibly these local distortions accompanied catastrophic lake drainage by jökulhlaup, analogous to crustal movements associated with man-made lakes. A relationship between crustal movement and the limit of a glacial advance is demonstrated. These findings have implications for other parts of the world affected by glacioisostatic uplift.
The UN Convention on the Rights of Persons with Disabilities (CRPD) has been adopted by national governments to advance the interests and wellbeing of people with psychosocial disabilities (PPSD). It is often assumed that the adoption of a ‘rights’ framework will advance the dignity and autonomy of PPSD. However, little is known about how families and communities understand ‘rights’. The present paper, based on research conducted in Santiago, Chile, takes a contextual approach to rights, asking: How do family carers of PPSD understand and use the idea of ‘rights’? How does the context of caregiving shape families’ understanding of rights?
Methods.
Four focus groups were conducted with a total of 25 family carers (predominantly mothers) of people diagnosed with schizophrenia and other severe neuropsychiatric conditions. Thematic analysis was conducted.
Results.
Carers’ experience of caregiving was marked by isolation, stigmatization, a lack of support and mistreatment by public services. Their family networks did not provide sustained help and support, and the public services they had used were characterized by scarce resources and inadequate support. Carers did not refer to rights of dignity or autonomy. Given an unsupportive context, and worries about who would care for their child after the carer's death, their primary interest in ‘rights’ was a right to guaranteed, long-term care. While carers endorsed the idea of universal, state-supported rights, appeals to compassion and the exchange of favours were spoken of as the most effective strategies for gaining a minimum level of services and support.
Conclusions.
Carers’ understandings, framed against a background of unmet needs and shaped by a history of unsatisfactory interactions with services and institutions, do not resonate with the principles of the CRPD. We suggest an expanded, relational struggle for rights that acknowledges the role of families and the tensions surrounding the distribution of rights within the family.
The present study examined, using rats as a model, the effects of sex and age of exposure to dietary soya components on serum total and soya-specific antibody content. In Expt 1, Sprague–Dawley rats at 50 d of age were fed diets containing 20 % casein or 20 % alcohol-washed soya protein isolate (SPI) with or without supplemental isoflavones (ISF, 250 mg/kg diet) for 70, 190 or 310 d. The offspring were fed the same diets as their parents. In Expt 2, juvenile Sprague–Dawley rats at 30 d of age were fed diets containing 20 % casein with or without supplemental ISF (50 mg/kg diet) or increasing amounts of alcohol-washed SPI (5, 10 or 20 %) for 90 d. Exposure of rats to dietary SPI before the age of 28 d increased serum total IgA and IgM, and induced the production of SPI-specific IgA, IgG, IgM and IgE antibodies. Feeding of juvenile or adult rats with SPI elevated serum total IgA in females, while the opposite occurred in males, and markedly stimulated the production of SPI-specific IgM in females and IgG in males. Our data suggest that the effects of soya proteins and ISF on the production of serum total and SPI-specific antibodies appear to be sex dependent and also related to the age of exposure to soya in rats. However, the physiological significance of these immune responses remains to be determined.
Computer-based tests with randomly generated questions allow a large number of different tests to be generated. Given a fixed number of alternatives for each question, the number of tests that need to be generated before all possible questions have appeared is surprisingly low.
AMS subject classification (MSC2010) 60G70, 60K99
Introduction
The use of computer-based tests in which questions are randomly generated in some way provides a means whereby a large number of different tests can be generated; many universities currently use such tests as part of the student assessment process. In this paper we present findings that illustrate that, although the number of different possible tests is high and grows very rapidly as the number of alternatives for each question increases, the average number of tests that need to be generated before all possible questions have appeared at least once is surprisingly low. We presented preliminary findings along these lines in Cornish et al. (2006).
A computer-based test consists of q questions, each (independently) selected at random from a separate bank of a alternatives. Let Nq be the number of tests one needs to generate in order to see all the aq questions in the q question banks at least once. We are interested in how, for fixed a, the random variable Nq grows with the number of questions q in the test.
A method for solving quite general three-dimensional incompressible flow problems, in particular those described by the Navier–Stokes equations, is presented. The essence of the method is the expression of the velocity in terms of scalar and vector potentials, which are the three-dimensional generalizations of the two-dimensional stream function, and which ensure that the equation of continuity is satisfied automatically. Although the method is not new, a correct but simple and unambiguous procedure for using it has not been presented before.
Superalloys based on platinum-group metals are being developed for high-temperature applications. These alloys have two-phase structures comprising either ordered precipitates in a matrix analogous to the nickel-based superalloys or a fine dispersion of oxide particles in a matrix analogous to oxide-dispersion-strengthened nickel-based alloys. Currently, alloys based on iridium, rhodium, and platinum have been obtained. This article reviews the rationale of developments and the progress made in this area. Oxidation and compression tests as well as characterization with scanning electron microscopy and transmission electron microscopy were undertaken. These tests showed encouraging results, and further work is being done on new alloying additions and tensile testing.
In the realm of copyright, films and other audiovisual productions have become the archetypal complex work. The range of creative participants in the production of a film is often extensive, the risk to investors is considerable. Yet the prospects for the lucky few who succeed in scoring a hit with viewers are celestial: a powerful flow of revenues from the film itself, at the box-office and on television, a parallel stream from the sale of merchandise, and ultimately the chance of making sequels and other follow-ons. The legal organisation behind these exploitations turns at root on copyright protection and in economic detail upon contractual relationships. In future, technological controls over the exploitation of digital material will become increasingly crucial. The governing law has developed in different countries in response to pressures from national film-makers and also from powerful outsiders, led by the Leviathan that is Hollywood. On the film scene in Europe, Americanophobia is never far from the surface – as the negotiators of the GATT–WTO accord discovered as it was ripening for signature in 1994.
Beside these festering jealousies, there are differences of basic attitude: is film a grubby little form of mass entertainment, a tinsel make-believe which ordinary people need and will pay for in large numbers? Or is it the great new art of the twentieth century, through which directors illuminate our human condition in comparable degree with the greatest masters of language and music and the plastic arts?
This essay is not intended for specialists in intellectual property or European Community law. It is addressed to those who, from time to time, have to wrestle with the baffling issue of when it is legal to employ patents for inventions as a means of resisting ‘parallel importation’, and when as a matter of policy it is desirable to do so. My underlying aim is to set out arguments so that readers can judge for themselves. The arguments vary in relation to the different types of intellectual property – a factor which is often ignored in public debates. The distinctions involved are accordingly my starting point.
Intellectual property rights (IPRs) – patents, copyright, trade marks and so on – exist to prevent those who do not have the rightholder's licence from producing and trading in certain goods or services where otherwise they would be entitled to do so. IPRs indirectly provide their owners with a freedom to trade in a market without direct competition from those with whom they have no connection. Thus composers and record producers have copyrights which they can use to attack pirates who have made illegitimate copies of their music and records; patentees of inventions can prevent their rivals from incorporating the inventive idea into their products, machines and processes.
In essence, IPRs exist on a State-by-State basis and give rights against trading activities within national (or occasionally regional) boundaries. This strict concept of territoriality means that, for instance, patents for a given invention must be obtained for each country.
Intellectual Property is not a term with a standard meaning. Traditionally it was used to describe the copyright protection of authors and to distinguish this from industrial property, i.e., Patents for inventions, industrial design rights, plant variety rights, trade marks and the like. Recently it has become an umbrella for copyright, rights related to it and the various forms of industrial property. The new generic grouping has been needed for a world where demand for these rights has risen to an altogether new pitch. In part this is the consequence of extraordinary advances in technologies which make recorded information easily and precisely reproducible; and partly it supports the quest of advanced economies to conserve superior knowledge as a weapon in international trade.
The coproduct of a family of Kleene algebras is determined firstly by describing the maximal homomorphic image of a De Morgan algebra in the subvariety of Kleene algebras and, secondly, by characterizing the categorical product in the dual category of Kleene spaces.
The dual of the category of De Morgan algebras is described in terms of compact totally ordered-disconnected ordered topological spaces which possess an involutorial homeomorphism that is also a dual order-isomorphism. This description is used to study the coproduct of an arbitrary collection of De Morgan algebras and also to represent the coproduct of two De Morgan algebras in terms of the continuous order-preserving functions from the Priestley space of one algebra to the other algebra, endowed with the discrete topology. In addition, it is proved that the coproduct of a family of Kleene algebras in the category of De Morgan algebras is the same as the coproduct in the subcategory of Kleene algebras if and only if at most one of the algebras is not boolean.
The present Copyright Act of the United Kingdom was passed in 1956, when modern photocopying was in its comparative infancy. The lusty cries of the novel technology were echoed in the Act. For instance, publishers secured a new form of copyright -in the typographical arrangement of an edition– which was protected against unauthorised reproduction by any photographic or similar process for 25 years from first publication of the edition. The Act also attempted to strike a balance over photocopying and similar practices. But the result was a cautious compromise which simply has not worked.