The dynamics of solar magnetoconvection spans a wide range of spatial and temporal scales and extends from the interior to the corona. Using 3D radiative MHD simulations, we investigate the complex interactions that drive various phenomena observed on the solar surface, in the low atmosphere, and in the corona. We present results of our recent simulations of coronal dynamics driven by underlying magnetoconvection and atmospheric processes, using the 3D radiative MHD code StellarBox (Wray et al. 2018). In particular, we focus on the evolution of thermodynamic properties and energy exchange across the different layers from the solar interior to the corona.

The role of tachoclines, the thin shear layers that separate solid body from differential rotation in the interior of late-type stars, in stellar dynamos is still controversial. In this work we discuss their relevance in view of recent results from global dynamo simulations performed with the EULAG-MHD code. The models have solar-like stratification and different rotation rates (i.e., different Rossby number). Three arguments supporting the key role of tachoclines are presented: the solar dynamo cycle period, the origin of torsional oscillations and the scaling law of stellar magnetic fields as function of the Rossby number. This scaling shows a regime where the field strength increases with the rotation and a saturated regime for fast rotating stars. These properties are better reproduced by models that consider the convection zone and a fraction of the radiative core, naturally developing a tachocline, than by those that consider only the convection zone.

The mechanism by which sunspots are generated at the surface of the sun remains unclear. In the current literature two types of explanations can be found. The first one is related to the buoyant emergence of toroidal magnetic fields generated at the tachocline. The second one states that active regions are formed, from initially diffused magnetic flux, by MHD instabilities that develop in the near-surface layers of the Sun. Using the anelastic MHD code EULAG we address the problem of sunspot formation by performing implicit large-eddy simulations of stratified magneto-convection in a domain that resembles the near-surface layers of the Sun. The development of magnetic structures is explored as well as their effect on the convection dynamics. By applying a homogeneous magnetic field over an initially stationary hydrodynamic convective state, we investigate the formation of self-organized magnetic structures in the range of the initial magnetic field strength, 0.01 < B 0/B eq < 0.5, where B eq is the characteristic equipartition field strength.

We present multidimensional modeling of convection and oscillations in main-sequence stars somewhat more massive than the Sun, using three separate approaches: 1) Using the 3-D planar StellarBox radiation hydrodynamics code to model the envelope convection zone and part of the radiative zone. Our goals are to examine the interaction of stellar pulsations with turbulent convection in the envelope, excitation of acoustic modes, and the role of convective overshooting; 2) Applying the spherical 3-D MHD ASH (Anelastic Spherical Harmonics) code to simulate the core convection and radiative zone. Our goal is to determine whether core convection can excite low-frequency gravity modes, and thereby explain the presence of low frequencies for some hybrid γ Dor/δ Sct variables for which the envelope convection zone is too shallow for the convective blocking mechanism to drive gravity modes; 3) Applying the ROTORC 2-D stellar evolution and dynamics code to calculate evolution with a variety of initial rotation rates and extents of core convective overshooting. The nonradial adiabatic pulsation frequencies of these nonspherical models are calculated using the 2-D pulsation code NRO. We present new insights into pulsations of 1-2 M⊙ stars gained by multidimensional modeling.

The search for disease resistance in wild types is continuing, in order to introduce resistant genes from wild relatives. In this study, we found that the wild melon Cucumis prophetarum was comparably more tolerant to salinity, the damping-off disease caused by the fungus Rhizoctonia solani and the root-knot nematode Meloidogyne incognita. The percentage of wild melon survival was 60% compared to that of the cultivated cucumber Cucumis sativus, which was 15%, when irrigated with NaCl at a concentration of 2500 ppm; and 96% for the wild melon compared with 44% for the cultivated cucumber when irrigated with CaSO4.2H2O at a concentration of 1000 ppm. Wild melon plants were more tolerant to R. solani attack, as only 20% of the plants were infested compared with 100% of infestation observed for the cultivated cucumber. The average number of nematode galls was 250 per plant on the cultivated cucumber when compared with 6.3 per plant on the wild species. Wild melon could be a potential source of resistant or tolerant genes that can be transferable to cultivated cucumbers.

By conducting a case-control study in two university hospitals, we explored the association between modifiable risk behaviours and diarrhoea. Children aged <5 years attending outpatient clinics for diarrhoea were matched by age and sex with controls. Data were collected on family demographics, socioeconomic indicators, and risk behaviour practices. Two rectal swabs and a stool specimen were collected from cases and controls. Samples were cultured for bacterial pathogens using standard techniques and tested by ELISA to detect rotavirus and Cryptosporidium spp. Four hundred cases and controls were enrolled between 2007 and 2009. The strongest independent risk factors for diarrhoea were: presence of another household member with diarrhoea [matched odds ratio (mOR) 4·9, 95% CI 2·8–8·4] in the week preceding the survey, introduction to a new kind of food (mOR 3, 95% CI 1·7–5·4), and the child being cared for outside home (mOR 2·6, 95% CI 1·3–5·2). While these risk factors are not identifiable, in some age groups more easily modifiable risk factors were identified including: having no soap for handwashing (mOR 6·3, 95% CI 1·2–33·9) for children aged 7–12 months, and pacifier use (mOR 1·9, 95% CI 1·0–3·5) in children aged 0–6 months. In total, the findings of this study suggest that community-based interventions to improve practices related to sanitation and hygiene, handwashing and food could be utilized to reduce the burden of diarrhoea in Egyptian children aged <5 years.

Convective turbulent motions in the solar interior, as well as the mean flows resulting from them, determine the evolution of the solar magnetic field. With the aim to get a better understanding of these flows we study anelastic rotating convection in a spherical shell whose stratification resembles that of the solar interior. This study is done through numerical simulations performed with the EULAG code. Due to the numerical formulation, these simulations are known as implicit large eddy simulations (ILES), since they intrinsically capture the contribution of, non-resolved, small scales at the same time maximizing the effective Reynolds number. We reproduce some previous results and find a transition between buoyancy and rotation dominated regimes which results in anti-solar or solar like rotation patterns. Even thought the rotation profiles are dominated by Taylor-Proudman columnar rotation, we are able to reproduce the tachocline and a low latitude near-surface shear layer. We find that simulations results depend on the grid resolution as a consequence of a different sub-grid scale contribution.

Diversity within Shigella dysenteriae (n=40) and Shigella boydii (n=30) isolates from children living in Egypt aged <5 years was investigated. Shigella-associated diarrhoea occurred mainly in summer months and in children aged <3 years, it commonly presented with vomiting and fever. Serotypes 7 (30%), 2 (28%), and 3 (23%) accounted for most of S. dysenteriae isolates; 50% of S. boydii isolates were serotype 2. S. dysenteriae and S. boydii isolates were often resistant to ampicillin, chloramphenicol and tetracycline (42%, 17%, respectively), although resistance varied among serotypes. Pulsed-field gel electrophoresis separated the isolates into distinct clusters correlating with species and serotype. Genetic differences in trimethoprim/sulfamethoxazole and β-lactam-encoding resistance genes were also evident. S. dysenteriae and S. boydii are genetically diverse pathogens in Egypt; the high level of multidrug resistance associated with both pathogens and resistance to the most available inexpensive antibiotics underlines the importance of continuing surveillance.

Filamentary structure is a fundamental property of the magnetized solar plasma. Recent high-resolution observations and numerical simulations have revealed close links between the filamentary structures and plasma dynamics in large-scale solar phenomena, such as sunspots and magnetic network. A new emerging paradigm is that the mechanisms of the filamentary structuring and large-scale organization are natural consequences of turbulent magnetoconvection on the Sun. We present results of 3D radiative MHD large-eddy simulations (LES) of magnetic structures in the turbulent convective boundary layer of the Sun. The results show how the initial relatively weak and uniformly distributed magnetic field forms the filamentary structures, which under certain conditions gets organized on larger scales, creating stable long-living magnetic structures. We discuss the physics of magnetic self-organization in the turbulent solar plasma, and compare the simulation results with observations.

We use 3D radiative MHD simulations of the upper turbulent convection layer for investigation of physical mechanisms of formation of magnetic structures on the Sun. The simulations include all essential physical processes, and are based of the LES (Large-Eddy Simulations) approach for describing the sub-grid scale turbulence. The simulation domain covers the top layer of the convection zone and the lower atmosphere. The results reveal a process of spontaneous formation of stable magnetic structures from an initially weak vertical magnetic field, uniformly distributed in the simulation domain. The process starts concentration of magnetic patches at the boundaries of granular cells, which are subsequently merged together into a stable large-scale structure by converging downdrafts below the surface. The resulting structure represents a compact concentration of strong magnetic field, reaching 6 kG in the interior. It has a cluster-like internal structurization, and is maintained by strong downdrafts extending into the deep layers.

It is known that physical properties of solar turbulent convection and oscillations strongly depend on magnetic field. In particular, recent observations from SOHO/MDI revealed significant changes of the wave properties in inclined magnetic field regions of sunspots, which affect helioseismic inferences. We use realistic 3D radiative MHD numerical simulations to investigate solar convection and oscillations and their relationship in the presence of inclined magnetic field. In the case of highly inclined and strong 1-1.5 kG field the solar convection develops filamentary structure and high-speed flows (Fig. 1a), which provide an explanation to the Evershed effect in sunspot penumbra (Kitiashvili, et al. 2009).

Thin Films of Azo Dye (1-Phenylazo-2-Naphthol) have been prepared by thermal evaporation technique onto quartz substrates held at about 300 K during the deposition process with different thicknesses range 625–880 nm. X-ray diffraction and the differential thermal analysis showed that the Azo Dye sample is crystalline nature and thermal stable in temperature range from room temperature to 100  $^{\circ}$ C. The optical constants (the refractive index n, the absorption index k and the absorption coefficient α) were calculated for Azo Dye (1-Phenylazo-2-Naphthol) thin films by using spectrophotometer measurements of the transmittance and reflectance at normal incidence in the spectral range 400–2200 nm. The obtained values of both n and k were found to be independent of the film thicknesses. The refractive index has anomalous behavior in the wavelength range 400–1000 nm besides a high energy transition at 2.385 eV. The optical parameters (the dispersion energy E d , the oscillation energy E o , the room temperature optical dielectric constant $\varepsilon_{l}$ , the lattice dielectric constant $\varepsilon_{L}$ , the high frequency dielectric constant $\varepsilon_{\infty}$ and the ratio of carrier concentration to the effective mass $N/m^{\ast}$ ) were calculated. The allowed optical transition responsible for optical absorption was found to be direct transition with optical energy gap of 1.5 eV for Azo Dye sample. The band tail obeys Urbach's empirical relation. 

Voltage characteristics of polysilicon thin films transistors (Poly-Si TFTs) are related to basic material and device parameters. Understanding and modeling the electrical behavior of poly-Si TFT require knowledge of equivalent properties of polysilicon which are strongly affected by defects present in this material. A numerical analysis, which studies the electrical characteristics of small-grains poly-Si TFTs, has been investigated. The density of states (DOS) in the band gap is modeled by assuming an exponential distribution of deep and tail states. The proposed model evaluates the influence of both deep and tail states on the electrical conduction process and the dominant contribution of tail states on the threshold voltage values while the deep states in the middle of polysilicon gap controls the lower threshold regime. The surface potential and ON/OFF current ratio are also calculated. The comparison of the generated current-voltage characteristics obtained from numerical simulation TCAD-ATLAS with those reported in the literature show a good agreement.

The resistance of 32 melon lines to Tetranychus cinnabarinus (Boisduval) was studied in Israel. Average counts ten days after infestation, at the fourth-leaf stage, ranged from 3·5 to 57 mites per four leaf discs 1 cm in diameter; six lines had significantly low counts, ranging from 0·9 to 1·5 mites per four leaf discs. Fourteen of the lines were also tested at the flowering stage. No mites were found on two lines, and on a third line very few mites were observed. All three lines also had had significantly low mite counts at the fourth-leaf stage. The results suggest there is a definite variation among melon lines in resistance to mite infestation.