Febrile seizure (FS) in children is a common complication of infections with respiratory viruses and hand, foot and mouth disease (HFMD). We conducted a retrospective ecological time-series analysis to determine the temporal relationship between hospital attendances for FS and HFMD or respiratory virus infections. Epilepsy attendance was used as a control. Data from 2004 to 2012 FS and epilepsy hospital attendance, HFMD notifications to the Ministry of Health and from laboratory-confirmed viral respiratory infections among KK Women's and Children's Hospital inpatients were used. A multivariate linear regression analysis was conducted to evaluate the relationship between FS and the virus time series. Relative risks of FS by age were calculated using Bayesian statistical methods. Paediatric accident and emergency (A&E) attendances for FS were found to be associated with influenza A (extra 0.47 FS per influenza A case), B (extra 0.32 per influenza B case) and parainfluenza 3 (extra 0.35 per parainfluenza type 3 case). However, other viruses were not significantly associated with FS. None of the viruses were associated with epileptic seizure attendance. Influenza A, B and parainfluenza 3 viruses contributed to the burden of FS resulting in A&E attendance. Children at risk of FS should be advised to receive seasonal influenza vaccination.

We study the strengths of various notions of higher randomness: (i) strong ${\rm{\Pi }}_1^1$randomness is separated from ${\rm{\Pi }}_1^1$randomness; (ii) the hyperdegrees of ${\rm{\Pi }}_1^1$random reals are closed downwards (except for the trivial degree); (iii) the reals z in $NC{R_{{\rm{\Pi }}_1^1}}$ are precisely those satisfying $z \in {L_{\omega _1^z}}$ and (iv) lowness for ${\rm{\Delta }}_1^1$randomness is strictly weaker than that for ${\rm{\Pi }}_1^1$randomness.

We give a survey of the study of nonstandard models in recursion theory and reverse mathematics. We discuss the key notions and techniques in effective computability in nonstandard models, and their applications to problems concerning combinatorial principles in subsystems of second order arithmetic. Particular attention is given to principles related to Ramsey’s Theorem for Pairs.

Nanoscale superlattice-like (SLL) dielectric was employed to reduce the power consumption of the Phase-change random access memory (PCRAM) cells. In this study, we have simulated and found that the cells with the SLL dielectric have a higher peak temperature compared to that of the cells with the SiO2 dielectric after constant pulse activation, due to the interface scattering mechanism. Scaling of the SLL dielectric has resulted in higher peak temperatures, which can be even higher after material/structural modifications. Furthermore, the SLL dielectric has good material properties that enable the cells to have high endurance. This shows the effectiveness of the SLL dielectric for advanced memory applications.

Twelve strains of German cockroach, Blattella germanica (Linnaeus) were collected from various locations in Peninsular Malaysia and tested for their susceptibility to three groups of insecticides applied topically. The levels of resistance were low to high (2.8 to 92x) for carbamates (propoxur and bendiocarb), low (2.0 to 7.6x) for organophosphate (chlorpyrifos) and low to moderate (1.0 to 23x) for pyrethroids (cypermethrin and permethrin) when compared to a susceptible strain. Five strains, resistant to both cypermethrin and permethrin, were also resistant to DDT, phenothrin and deltamethrin. Propoxur resistance in ten strains was suppressed with the synergists, piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEFR), suggesting monooxygenase and esterase involvement in the resistance. However, the levels of resistance for cypermethrin and permethrin were not affected when using either PBO or DEFR.

We study the problem of existence of maximal chains in the Turing degrees. We show that:

1. ZF + DC + “There exists no maximal chain in the Turing degrees” is equiconsistent with ZFC + “There exists an inaccessible cardinal”

2. For all a ∈ 2ω, (ω1)L[a] = ω1 if and only if there exists a [a] maximal chain in the Turing degrees. As a corollary, ZFC + “There exists an inaccessible cardinal” is equiconsistent with ZFC + “There is no (bold face) maximal chain of Turing degrees”.

The growth temperature and properties of Ge4Sb3Te3 thin films are presented in this paper. The critical growth temperature of Ge4Sb3Te3 is between 300 and 340 °C. The Ge4Sb3Te3 films can only be grown on a substrate below the critical growth temperature. The typical resistivity and carrier density are in the order of 10-4 Ωcm and 1021 cm-3 for crystalline phase. It has a rock salt crystal structure with a lattice constant of 0.602 nm. Ge4Sb3Te3 has a better thermal stability but a lower crystallization speed than Ge2Sb2Te5.

In this paper, a three-dimensional finite-element modeling is performed for the analyses of Chalcogenide Random Access Memory (C-RAM), a non-rotation nonvolatile phase change memory cell. The thermal effect generated by an incident electric pulse was mainly discussed. Thermal performances of the cell as a result of electrical and geometrical variations were quantified. Current density distribution, temperature profiles, temperature history, heating rate, cooling rate, and heat flow characteristics were obtained and analyzed. The study is useful for the failure analysis of the C-RAM.

A solid polythiophene pellet was ablated by a KrF excimer laser beam to deposit thin films on silicon substrates. The laser-ablated plasma was studied by optical emission spectroscopy to identify the photon-breaking of C–S bonds in the ablated heterocycles. Raman and x-ray photoelectron spectroscopy measurements of the deposited thin films also supported the selective photon-induced bond breaking. After eliminating sulfur in the molecular structures, the thin films appeared to be composed of cubic nanocrystals with a uniform size of 240 nm. X-ray diffraction measurement determined the cubic crystal structures with a lattice constant of α =3.38 Å and suggested a quasi-onedimensional carbon chain structure along the body diagonal of the cube.

Thin films of polythiophene, a kind of polyheterocyclic compound with hydrogen function groups, were deposited by KrF excimer laser ablation of a compressed solid target in a vacuum chamber. The laser pulse fluence was approximately selected at 2 J/cm2 with a pulse duration of 25 ns. The structural, topographic, and electronic properties of the deposited thin films were analyzed by atomic force microscope, x-ray diffraction, and Raman and infrared spectroscopy measurements. Deposited thin films were observed to have good crystal properties and to be composed of crystalline cubes with a uniform size of 0.1 μm. The electronic structure of the deposited thin films should be different from the target materials, resulting from the laser irradiation effects. The influence of the deposition temperature on the structural and electronic properties of the deposited thin films was studied.

The study of recursion theory on models of fragments of Peano arithmetic has hitherto been concentrated on recursively enumerable (r.e.) sets and their degrees (with a few exceptions, such as that in [2] on minimal degrees). The reason for such a concerted effort is clear: priority arguments have occupied a central position in post Friedberg-Muchnik recursion theory, and after almost forty years of intensive development in the subject, they are still the essential tools on which investigations of r.e. sets and their degrees depend. There are two possible approaches to the study within fragments of arithmetic: To give a general analysis of strategies, and identify their proof-theoretic strengths (for example in [6] on infinite injury priority methods), or to consider specific theorems in recursion theory, and, if possible, pinpoint the exact levels of induction provably equivalent to the theorems. The work reported in this paper belongs to the second approach. More precisely, we single out two infinitary injury type constructions of r.e. sets—one concerning maximal sets and the other based on the notion of the jump operator—to be the topics of study.

Theoretical studies and design of quantum well lasers employing InGaN require material parameters for both GaN and InN. However, the Luttinger-like effective-mass parameters for InN are currently unavailable. In this work, we extract effective-mass parameters for wurtzite GaN and InN from their electronic band structures calculated using the Empirical Pseudopotential Method (EPM). We obtain the electron and hole (including the heavy- (HH), light- (LH), and crystal-field split-off (CH) holes) effective-masses at the Γ point in the kz and the in-plane kx-ky plane) directions using a parabolic fit. In addition, the hole effective-mass parameters are derived using the 6×6 effective-mass Hamiltonian and the k.p method. Our results will be useful for material design in wide-gap nitride-based semiconductor lasers containing InGaN.

Dislocations and traps in MBE grown p-InGaAs/GaAs lattice-mismatched heterostructures are investigated by Cross-section Transmission Electron Microscopy (XTEM), Deep Level Transient Spectroscopy (DLTS) and Photo-luminescence (PL). The misfit dislocations and the threading dislocations observed by XTEM in different samples with different In mole fractions and different InGaAs layer thickness generally satisfy the Dodson-Tsao's plastic flow critical layer thickness curve. The threading dislocations in bulk layers introduce three hole trap levels HI, H2 and H5 with DLTS activation energies of 0.32 eV, 0.40 eV, 0.88 eV, respectively, and one electron trap El with DLTS activation energy of 0.54 eV. The misfit dislocations in relaxed InGaAs/GaAs interface induce a hole trap level H4 with DLTS activation energy between the range of 0.67–0.73 eV. All dislocation induced traps are nonradiative recombination centers which greatly degrade the optical property of the InGaAs/GaAs layers.

The valence subband structures, density-of-states, and optical gain of (0001) wurtzite (WZ) InxGa1-xN/GaN quantum wells (QWs) are studied using a numerical approach without analytical approximations. We used the effective-mass parameters of GaN and InN derived using the Empirical Pseudopotential Method. By varying the well width and mole fraction of In in the well material, the effects of quantum confinement and compressive strain are studied. A narrower well width and a higher In mole fraction in the well lead to TE enhancement and TM suppression of the optical gain. From the relationship between the optical gain and the radiative current density, we obtain the transparent current density for a single QW to be 200 A/cm2. Further, we analyze the InxGa1-xN/GaN/AlGaN separate confinement heterostructure multiple-QW laser structure. It is shown that a suitable combination of well width and number of QWs should be selected in optimizing the threshold current density in such MQW lasers