The Effect of M-Commerce on Nigeria’s Economic Growth

This paper seeks to assess the implications of mobile commerce on the economy of Nigeria. Ordinary least square technique, correlation matrix test and Granger –causality test were employed to measure the extent to which the gross domestic product was influenced. The result showed that internet penetration and telecommunication contribution impacted positively on gross domestic product of Nigeria; mobile penetration had negative and statistically insignificant effect on gross domestic product; while mobile penetration aids m-commerce in Nigeria, it negatively affects Nigeria’s trade balance and economic growth due to huge imports of mobile phones. It is therefore recommended that government should encourage local production of mobile phones and where she lacks the technology to do so, encourage foreign direct investment inflow of foreign mobile phone producers in Nigeria. Keywords: economic growth; internet penetration; m-commerce (mobile commerce); mobile penetration

An Evaluation of the Efficacy of GraphoGame Rime for Promoting English Phonics Knowledge in Poor Readers

© Copyright © 2020 Ahmed, Wilson, Mead, Noble, Richardson, Wolpert and Goswami. Here, we report further analysis of data drawn from a Randomized Controlled Trial (RCT) run in the United Kingdom designed to evaluate the efficacy of an adaptive software game to aid the learning of English phonics, GraphoGame Rime. We evaluate the efficacy of GraphoGame Rime for the “top half” of players in the RCT, children aged 6 to 7 years who played above the group mean play progress point (95 children). We also analyze three sub-groupings of this cohort. The GraphoGame family of games in different languages was originally designed to support children at family risk of dyslexia, hence we analyzed data for the subgroup of the GraphoGame Rime children who were struggling in school and had Individual Education Plans (IEPs). Secondly, we analyzed data from the younger children in the RCT, born in the Spring and Summer months, as international studies of GraphoGame have found the strongest effects during the first year of reading tuition and our participants were in their second year of reading tuition. Finally, we analyzed GraphoGame Rime data from players in schools rated as “requiring improvement.” Schools that are found to be “requiring improvement” in the United Kingdom are encouraged to use additional teaching strategies to achieve better outcomes. GraphoGame Rime is relatively cheap to acquire and easy to implement, hence if it offers significant gains over “business-as-usual” this would be a valulable additional strategy for such schools. We find that GraphoGame Rime is more effective than “business-as-usual” in developing knowledge of English phonics for all of the groupings analyzed. We conclude that the supplementary use of GraphoGame Rime in addition to ongoing classroom literacy instruction can benefit children in learning phonic decoding and spelling skills.Wellcome Trus

Finger patterns produced by thermomagnetic instability in superconductors

A linear analysis of thermal diffusion and Maxwell equations is applied to study the thermomagnetic instability in a type-II superconducting slab. It is shown that the instability can lead to formation of spatially nonuniform distributions of magnetic field and temperature. The distributions acquire a finger structure with fingers perpendicular to the screening current direction. We derive the criterion for the instability, and estimate its build-up time and characteristic finger width. The fingering instability emerges when the background electric field is larger than a threshold field, $E>E_c$, and the applied magnetic field exceeds a value $H_fing \propto 1/\sqrt{E}$. Numerical simulations support the analytical results, and allow to follow the development of the fingering instability beyond the linear regime. The fingering instability may be responsible for the nucleation of dendritic flux patterns observed in superconducting films using magneto-optical imaging.Comment: 8 pages, 6 figures, accepted to Phys. Rev. B; (new version: minor changes

Flow Equations for N Point Functions and Bound States

We discuss the exact renormalization group or flow equation for the effective action and its decomposition into one particle irreducible N point functions. With the help of a truncated flow equation for the four point function we study the bound state problem for scalar fields. A combination of analytic and numerical methods is proposed, which is applied to the Wick-Cutkosky model and a QCD-motivated interaction. We present results for the bound state masses and the Bethe-Salpeter wave function. (Figs. 1-4 attached as separate uuencoded post-script files.)Comment: 17 pages, HD-THEP-93-3

Supercooling across first-order phase transitions in vortex matter

Hysteresis in cycling through first-order phase transitions in vortex matter, akin to the well-studied phenomenon of supercooling of water, has been discussed in literature. Hysteresis can be seen while varying either temperature T or magnetic field H (and thus the density of vortices). Our recent work on phase transitions with two control variables shows that the observable region of metastability of the supercooled phase would depend on the path followed in H-T space, and will be larger when T is lowered at constant H compared to the case when H is lowered at constant T. We discuss the effect of isothermal field variations on metastable supercooled states produced by field-cooling. This path dependence is not a priori applicable to metastability caused by reduced diffusivity or hindered kinetics.Comment: Tex, 8 pages, 3 Postscripts figures. Submitted to Pramana - J. Physic

Evolution with hole doping of the electronic excitation spectrum in the cuprate superconductors

The recent scanning tunnelling results of Alldredge et al on Bi-2212 and of Hanaguri et al on Na-CCOC are examined from the perspective of the BCS/BEC boson-fermion resonant crossover model for the mixed-valent HTSC cuprates. The model specifies the two energy scales controlling the development of HTSC behaviour and the dichotomy often now alluded to between nodal and antinodal phenomena in the HTSC cuprates. Indication is extracted from the data as to how the choice of the particular HTSC system sees these two basic energy scales (cursive-U, the local pair binding energy and, Delta-sc, the nodal BCS-like gap parameter) evolve with doping and change in degree of metallization of the structurally and electronically perturbed mixed-valent environment.Comment: 19 pages, 5 figure

Perception of Filtered Speech by Children with Developmental Dyslexia and Children with Specific Language Impairments

Here we use two filtered speech tasks to investigate children’s processing of slow (<4 Hz) versus faster (∼33 Hz) temporal modulations in speech. We compare groups of children with either developmental dyslexia (Experiment 1) or speech and language impairments (SLIs, Experiment 2) to groups of typically-developing (TD) children age-matched to each disorder group. Ten nursery rhymes were filtered so that their modulation frequencies were either low-pass filtered (<4 Hz) or band-pass filtered (22 – 40 Hz). Recognition of the filtered nursery rhymes was tested in a picture recognition multiple choice paradigm. Children with dyslexia aged 10 years showed equivalent recognition overall to TD controls for both the low-pass and band-pass filtered stimuli, but showed significantly impaired acoustic learning during the experiment from low-pass filtered targets. Children with oral SLIs aged 9 years showed significantly poorer recognition of band pass filtered targets compared to their TD controls, and showed comparable acoustic learning effects to TD children during the experiment. The SLI samples were also divided into children with and without phonological difficulties. The children with both SLI and phonological difficulties were impaired in recognizing both kinds of filtered speech. These data are suggestive of impaired temporal sampling of the speech signal at different modulation rates by children with different kinds of developmental language disorder. Both SLI and dyslexic samples showed impaired discrimination of amplitude rise times. Implications of these findings for a temporal sampling framework for understanding developmental language disorders are discusse