Space-bandwidth-efficient realizations of linear systems

One can obtain either exact realizations or useful approximations of linear systems or matrix-vector products that arise in many different applications by implementing them in the form of multistage or multichannel fractional Fourier-domain filters, resulting in space-bandwidth-efficient systems with acceptable decreases in accuracy. Varying the number and the configuration of filters enables one to trade off between accuracy and efficiency in a flexible manner. The proposed scheme constitutes a systematic way of exploiting the regularity or structure of a given linear system or matrix, even when that structure is not readily apparent. © 1998 Optical Society of America

Novel strategy to prepare polyaniline - modified SiO2 / TiO2 composite particles

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Capillary Malformation-Arteriovenous Malformation Syndrome with Spinal Involvement

Capillary malformation-arteriovenous malformation (CM-AVM) is a recently identified autosomal dominant disorder. Arteriovenous lesions have been reported in the brain, limbs, and face. We report a 7-year-old patient with CM-AVM with spinal AVM, which is a rarely reported association

The prognostic role of prenatal MRI volumetric assessment in fetuses with isolated ventriculomegaly

In this prospective study, we aimed to establish the value of volumetric assessment by prenatal brain MRI in determining the prognosis of fetuses with isolated VM. A total of 23 fetuses with isolated VM were included in the study. Supratentorial cerebral parenchyma volume (PV) and ventricular volume (VV) were measured, and supratentorial ventricular/parenchymal volume (VV/PV) ratios were calculated. Pregnancy and postnatal neurodevelopmental outcomes up to two years of age were obtained and correlated with the volumetric measurements. VV was found to be strongly and positively correlated with ventricular dimension. There was a statistically significant difference between the VV/ PV ratios of the good and poor prognosis groups into which the cases had been categorized. The fetuses with a poor prognosis had a significantly higher VV/PV ratio. Volumetric parenchymal and ventricular measurements obtained by fetal brain MRI may contribute to future clinical studies concerning the evaluation of fetuses with VM and provide an important indicator in cases where management dilemmas arise. © 2015, Turkish Journal of Pediatrics. All rights reserved

Excited state dependent fast switching NLO behavior investigation of sp2 hybridized donor crystal as D-π-A push–pull switches

This research focused on the investigating electronic and optical properties of designed chromophores (TPTP1-TPTP5) to involve their comprehensive analysis, including geometry optimization, UV–Vis spectroscopy, analysis of the transition density matrix (TDM), and exploration of their nonlinear optical (NLO) responses. The chromophore TPTP1 and TPTP2 exhibit significant transitions, making them suitable for optical switching applications. The chromophore TPTP5 stood out with high values for linear polarizability (, 8.53 × 10-24 esu), first order polarizability β0 (3.86 × 10-24 esu), and second order hyperpolarizability (γ0, 6.41 × 10-24 esu), making it notable for its nonlinear optical response. A positive correlation was observed between their vertical ionization potential (VIP) and the γ0 related NLO response, indicating that higher VIP values correspond to stronger γ0 responses. Their UV–Vis spectroscopy was employed to examine the absorption properties of the chromophores, revealing the wavelengths (λmax) at which they absorbed light and their potential for light harvesting applications. The analysis of the TDM allowed for a deeper understanding of the redistribution of electron density during electronic transitions within the chromophores. This analysis provided valuable insights into the characteristics and nature of their excited states. Additionally, the research investigated the NLO responses of the chromophores, particularly focusing on their third harmonic generation (THG) properties. These NLO properties are crucial for potential applications in optical switches, frequency conversion, and optical signal processing. Overall, the findings from this research contribute to a comprehensive understanding of the electronic and optical properties of the designed chromophores. The obtained results open up new possibilities for their utilization in various technological fields, including light harvesting, photonics, and nonlinear optics

Germination Requirements of Androsace Villosa L. (Primulaceae)

We investigated the germination requirements of Androsace villosa L. (Hairy Androsace), which spreads on limestone or granite screes or ledges of rocky or turfy slopes and hilltops of the alpine zone. With seeds collect-ed from Uludag Mt. (Bursa, Turkey, 2200–2300 m a.s.l.), germination was studied in fresh seeds, seeds sub-jected to short-time moist chilling (15 d, +4°C), to GA3 (100, 150 and 250 ppm), and to chilling plus GA3. The hormone and moist chilling treatments were carried out in continuous darkness (20°C) and under a 12 h pho-toperiod at 20/10°C. Seeds maintained in darkness gave higher germination percentages than seeds maintained under a photoperiod. Germination rates rose to 90–97 % with 100–250 ppm GA3 and short-time moist chilling in continuous darkness (20°C). Seeds germinated rapidly under a combination of GA3 and short-time moist chilling in continuous darkness, generally giving the lowest mean germination times (4.4–5.0 d) among the treat-ments