Face Orientation Normalization Using Eye Positions

Despite the fact that progress in face recognition algorithms over the last decades has been made, changing lighting conditions and different face orientation still remain as a challenging problem. A standard face recognition system identifies the person by comparing the input picture against pictures of all faces in a database and finding the best match. Usually face matching is carried out in two steps： during the first step detection of a face is done by finding exact position of it in a complex background （various lightning condition）, and in the second step face identification is performed using gathered databases. In reality detected faces can appear in different position and they can be rotated, so these disturbances reduce quality of the recognition algorithms dramatically. In this paper to increase the identification accuracy we propose original geometric normalization of the face, based on extracted facial feature position such as eyes. For the eyes localization lbllowing methods has been used： color based method, mean eye template and SVM （Support Vector Machine） technique. Experimental investigation has shown that the best results for eye center detection can be achieved using SVM technique. The recognition rate increases statistically by 28% using face orientation normalization based on the eyes position.     

Gold-silver alloy nanoshells: a new candidate for nanotherapeutics and diagnostics

We have developed novel gold-silver alloy nanoshells as magnetic resonance imaging (MRI) dual T₁ (positive) and T₂ (negative) contrast agents as an alternative to typical gadolinium (Gd)-based contrast agents. Specifically, we have doped iron oxide nanoparticles with Gd ions and sequestered the ions within the core by coating the nanoparticles with an alloy of gold and silver. Thus, these nanoparticles are very innovative and have the potential to overcome toxicities related to renal clearance of contrast agents such as nephrogenic systemic fibrosis. The morphology of the attained nanoparticles was characterized by XRD which demonstrated the successful incorporation of Gd(III) ions into the structure of the magnetite, with no major alterations of the spinel structure, as well as the growth of the gold-silver alloy shells. This was supported by TEM, ICP-AES, and SEM/EDS data. The nanoshells showed a saturation magnetization of 38 emu/g because of the presence of Gd ions within the crystalline structure with r₁ and r₂ values of 0.0119 and 0.9229 mL mg^-1 s^-1, respectively (Au:Ag alloy = 1:1). T₁- and T₂-weighted images of the nanoshells showed that these agents can both increase the surrounding water proton signals in the T₁-weighted image and reduce the signal in T₂-weighted images. The as-synthesized nanoparticles exhibited strong absorption in the range of 600-800 nm, their optical properties being strongly dependent upon the thickness of the gold-silver alloy shell. Thus, these nanoshells have the potential to be utilized for tumor cell ablation because of their absorption as well as an imaging agent.     

Interaction between graphite oxide and Congo red in aqueous media

Interaction between graphite oxide and Congo red, a diazo dye containing NH₂ and SO₃ functional groups, was studied using UV–vis, FTIR, capillary electrophoresis and potentiometric methods. UV–vis experiments managed to elicit a colorful set of reactions, which were dependent on the sonication of solution. It was established that the molecules of Congo red after sonication are able to penetrate through the hydration shell and extract the protons attached to the functional groups on the surface of graphite oxide. Interaction between the graphite oxide particles and Congo red molecules is suggested to stabilize the aqueous suspensions of single-layer graphite oxide sheets. Potentiometric titration data show that the Congo red molecules adsorbed on the surface of graphite oxide are able to prevent the penetration of OH⁻ ions to reach the acidic functional groups inside the graphite oxide stacks. Electrostatic repulsion among these functional groups is quite high. Ionization of the graphite oxide colloidal particles with adsorbed Congo red molecules leads to the significant changes in their conformation.     

High-power bipolar multilevel pulsed electroporator

A novel, compact, high-voltage, bipolar electroporator is reported that produces single or multiple, symmetrical or asymmetrical, high-power square wave pulses up to ±1 kV and 100 A. A wide 1 μs to 10 ms pulse duration is provided with high resolution of 1 V and 0.5 μs. The device provides increased flexibility due to enhanced control of the pulse shape and delivered energy.     

Charge transition levels of the Ge dangling bond defect at Ge/insulator interfaces

We calculate defect levels of dangling bonds in germanium using hybrid density functionals. To validate our approach, we first consider the dangling bond in silicon finding two well-separated defect levels, in excellent correspondence with their experimental location. Application of our scheme to the dangling bond in germanium then yields two very close defect levels lying just above the valence band, consistent with the location of the experimentally determined charge neutrality level. The small correlation energy and the proximity to the valence band edge provide an explanation for the absence of clear defect signatures in electrical and electron spin resonance experiments.     

Noctilucent clouds: modern ground-based photographic observations by a digital camera network

Noctilucent, or "night-shining," clouds (NLCs) are a spectacular optical nighttime phenomenon that is very often neglected in the context of atmospheric optics. This paper gives a brief overview of current understanding of NLCs by providing a simple physical picture of their formation, relevant observational characteristics, and scientific challenges of NLC research. Modern ground-based photographic NLC observations, carried out in the framework of automated digital camera networks around the globe, are outlined. In particular, the obtained results refer to studies of single quasi-stationary waves in the NLC field. These waves exhibit specific propagation properties--high localization, robustness, and long lifetime--that are the essential requisites of solitary waves.     

The influence of lactic acid fermentation on biogenic amines and volatile compounds formation in flaxseed and the effect of flaxseed sourdough on the quality of wheat bread

The aim of the study was to investigate if differences in acidification, biogenic amines (BA) and volatile compounds (VC) occurred when Lactobacillus sakei KTU05-6, Pediococcus acidilactici KTU05-07 and Pediococcus pentosaceus KTU05-8 are used as starters in solid state fermentation of flaxseed and the impact of flaxseed sourdough on the wheat bread making process assessed.     

Single photon counting at telecom wavelength and quantum key distribution

Abstract

A brief overview is given of single photon detector performance requirements for quantum cryptography applications. The analysis is made with respect to restrictions necessary to secure the quantum key distribution channel. InGaAs/InP avalanche photodiode performance is analysed for single photon counting at 1550 nm. Quantum efficiency, dark current and afterpulsing probability (for times up to 100μs after an initial avalanche) are studied in a wider temperature range than previously reported (0deg; C to –80deg;C). We show that photon counting is a bottle-neck in current quantum key distribution systems and provides the source for future performance improvement.     

Isolation,identification and activity of natural antioxidants from horehound (Marrubium vulgare L.) cultivated in Lithuania

In an earlier screening of Lithuanian plants, horehound (Marrubium vulgare) showed good antioxidant activity and as this species is used in herbal teas and cough pastilles it was selected for further investigation. Some fractions of the aerial parts were strong scavengers of the model free radicals DPPH and ABTS⁺. Activity in the β-carotene bleaching assay and the rapeseed oil oxidation assay was lower. Several active compounds were observed in the crude methanol–water extract, and in butanol and methyl tert-butyl ether fractions using HPLC with on-line radical scavenging detection. After multi-step fractionation of these fractions five compounds possessing radical scavenging activity were purified and their structures were elucidated by NMR and MS as 5,6-dihydroxy-7,4′-dimethoxyflavone (syn. ladanein), 7-O-β-glucopyranosyl luteolin, 7-O-β-glucuronyl luteolin, verbascoside and forsythoside B. Their activities were tested in off-line DPPH and ABTS⁺ free radical scavenging assays, and compared with the antioxidants rosmarinic acid and Trolox.