The relationship between internet addiction, attention deficit hyperactivity symptoms and online activities in adults

Aim: The objective of this study was to examine the relationship between Internet Addiction (IA), Attention Deficit Hyperactivity Disorder (ADHD) symptoms and online activities in an adult population. Methods: A sample of 400 individuals aged 18 to 70 completed the Adult ADHD Self-Report Scale (ASRS), Young's Internet Addiction Test, and their preferred online activities. Results: A moderate association was found between higher levels of ADHD symptoms and IA. The best predictors of IA scores were ADHD symptoms, age, playing online games and spending more time online. Conclusion: Our findings further support a positive relationship between ADHD symptoms and excessive internet use

British economic growth : 1270 - 1870

We provide annual estimates of GDP for England between 1270 and 1700 and for Great Britain between 1700 and 1870, constructed from the output side. The GDP data are combined with population estimates to calculate GDP per capita. We find English per capita income growth of 0.20 per cent per annum between 1270 and 1700, although growth was episodic, with the strongest growth during the Black Death crisis of the fourteenth century and in the second half of the seventeenth century. For the period 1700-1870, we find British per capita income growth of 0.48 per cent, broadly in line with the widely accepted Crafts/Harley estimates. This modest trend growth in per capita income since 1270 suggests that, working back from the present, living standards in the late medieval period were well above “bare bones subsistence”. This can be reconciled with modest levels of kilocalorie consumption per head because of the very large share of pastoral production in agriculture

Increased microsaccade rate in individuals with ADHD traits

Microsaccades are involuntary, small, jerk-like eye-movements with high-velocity that are observed during fixation. Abnormal microsaccade rates and characteristics have been observed in a number of psychiatric and developmental disorders. In this study, we examine microsaccade differences in 43 non-clinical participants with high and low levels of ADHD-like traits, assessed with the Adult ADHD Self-Report Scale (ASRS, Kessler, Adler, et al., 2005). A simple sustained attention paradigm, which has been previously shown to elicit microsaccades, was employed. A positive correlation was found between ADHD-like traits and binocular and monocular microsaccade rates. No other differences in microsaccade properties were observed. The relationship between ADHD traits and microsaccades suggests that abnormal oculomotor behaviour is a core deficit in ADHD and could potentially lead to the development of a biomarker for the disorder

The relationship between ADHD traits and sensory sensitivity in the general population

Preliminary studies in children and adults with Attention Deficit Hyperactivity Disorder (ADHD) report both hypo-responsiveness and hyper-responsiveness to sensory stimuli, as well as problems modulating sensory input. As it has been suggested that those with ADHD exist at the extreme end of a continuum of ADHD traits, which are also evident in the general population, we investigated the link between ADHD and sensory sensitivity in the general population. Two online questionnaires measuring ADHD traits and sensory responsivity across various sensory domains were administered to 234 participants. Results showed a highly significant positive correlation between the number of ADHD traits and the frequency of reported sensory processing problems. An increased number of sensory difficulties across all modalities was associated with the level of ADHD. Furthermore, ADHD traits predicted sensory difficulties and exploratory factor analysis revealed a factor that combined ADHD trait and sensory processing items. This is the first study to identify a positive relationship between sensory processing and ADHD traits in the general population. Our results suggest that sensory difficulties could be part of the ADHD phenotype

An Improved Private Mechanism for Small Databases

We study the problem of answering a workload of linear queries $\mathcal{Q}$, on a database of size at most $n = o(|\mathcal{Q}|)$ drawn from a universe $\mathcal{U}$ under the constraint of (approximate) differential privacy. Nikolov, Talwar, and Zhang~\cite{NTZ} proposed an efficient mechanism that, for any given $\mathcal{Q}$ and $n$, answers the queries with average error that is at most a factor polynomial in $\log |\mathcal{Q}|$ and $\log |\mathcal{U}|$ worse than the best possible. Here we improve on this guarantee and give a mechanism whose competitiveness ratio is at most polynomial in $\log n$ and $\log |\mathcal{U}|$, and has no dependence on $|\mathcal{Q}|$. Our mechanism is based on the projection mechanism of Nikolov, Talwar, and Zhang, but in place of an ad-hoc noise distribution, we use a distribution which is in a sense optimal for the projection mechanism, and analyze it using convex duality and the restricted invertibility principle.Comment: To appear in ICALP 2015, Track

English economic growth, 1270-1700

We provide annual estimates of GDP for England over the period 1270-1700, constructed from the output side. The GDP data are combined with population estimates to calculate GDP per capita. Sectoral price data and estimates of nominal GDP are also provided. We find per capita income growth of 0.20 per cent per annum, although growth was episodic, with the strongest growth after the Black Death and in the second half of the seventeenth century. Living standards in the late medieval period were well above “bare bones subsistence”, although levels of kilocalorie consumption per head were modest because of the very large share of pastoral production in agriculture

Efficient Method for Computing Lower Bounds on the pp-radius of Switched Linear Systems

This paper proposes lower bounds on a quantity called $L^p$-norm joint spectral radius, or in short, $p$-radius, of a finite set of matrices. Despite its wide range of applications to, for example, stability analysis of switched linear systems and the equilibrium analysis of switched linear economical models, algorithms for computing the $p$-radius are only available in a very limited number of particular cases. The proposed lower bounds are given as the spectral radius of an average of the given matrices weighted via Kronecker products and do not place any requirements on the set of matrices. We show that the proposed lower bounds theoretically extend and also can practically improve the existing lower bounds. A Markovian extension of the proposed lower bounds is also presented

Investigating students' success in solving and attitudes towards context-rich open-ended problems in chemistry

Much research has been carried out on how students solve algorithmic and structured problems in chemistry. This study is concerned with how students solve open-ended, ill-defined problems in chemistry. Over 200 undergraduate chemistry students solved a number of open-ended problem in groups and individually. The three cognitive variables of working memory, M capacity and field dependence-independence were measured. A pre and post activity attitudes questionnaire was administered. The results show that there is a difference between the cognitive variables required for success in traditional algorithmic problems and open-ended problems. The context-rich open-ended problems significantly shifted students' attitudes towards problem solving

Electron Positron Annihilation Radiation from SgrA East at the Galactic Center

Maps of the Galactic electron-positron annihilation radiation show evidence for three distinct and significant features: (1) a central bulge source, (2) emission in the Galactic plane, and (3) an enhancement of emission at positive latitudes above the Galactic Center. In this paper, we explore the possibility that Sgr A East, a very prominent radio structure surrounding the Galactic nucleus, may be a significant contributer to the central bulge feature. The motivation for doing so stems from a recently proposed link between this radio object and the EGRET gamma-ray source 2EG J1746-2852. If this association is correct, then Sgr A East is also expected to be a source of copious positron production. The results presented here show that indeed Sgr A East must have produced a numerically significant population of positrons, but also that most of them have not yet had sufficient time to thermalize and annihilate. As such, Sgr A East by itself does not appear to be the dominant current source of annihilation radiation, but it will be when the positrons have cooled sufficiently and they have become thermalized. This raises the interesting possibility that the bulge component may be due to the relics of earlier explosive events like the one that produced Sgr A East.Comment: This manuscript was prepared with the AAS Latex macros v4.0 It is 37 pages long and has 16 figure