Magnetic dipole radiation tailored by substrates: numerical investigation

Nanoparticles of high refractive index materials can possess strong magnetic polarizabilities and give rise to artificial magnetism in the optical spectral range. While the response of individual dielectric or metal spherical particles can be described analytically via multipole decomposition in the Mie series, the influence of substrates, in many cases present in experimental observations, requires different approaches. Here, the comprehensive numerical studies of the influence of a substrate on the spectral response of high- index dielectric nanoparticles were performed. In particular, glass, perfect electric conductor, gold, and hyperbolic metamaterial substrates were investigated. Optical properties of nanoparticles were characterized via scattering cross-section spectra, electric field profiles, and induced electric and magnetic moments. The presence of substrates was shown to introduce significant impact on particle's magnetic resonances and resonant scattering cross-sections. Variation of substrate material provides an additional degree of freedom in tailoring properties of emission of magnetic multipoles, important in many applications.Comment: 10 page, 28 figure

Microscopic model of Purcell enhancement in hyperbolic metamaterials

We study theoretically a dramatic enhancement of spontaneous emission in metamaterials with the hyperbolic dispersion modeled as a cubic lattice of anisotropic resonant dipoles. We analyze the dependence of the Purcell factor on the source position in the lattice unit cell and demonstrate that the optimal emitter position to achieve large Purcell factors and Lamb shifts are in the local field maxima. We show that the calculated Green function has a characteristic cross-like shape, spatially modulated due to structure discreteness. Our basic microscopic theory provides fundamental insights into the rapidly developing field of hyperbolic metamaterials.Comment: 9 pages, 11 figure

Extremely short-length surface plasmon resonance sensors

The impact of the system design on the control of coupling between planar waveguide modes and surface plasmon polaritons (SPP) is analyzed. We examine how the efficiency of the coupling can be enhanced by an appropriate dimensioning of a multi-layer device structure without using additional gratings. We demonstrate that by proper design the length of the device can be dramatically reduced through fabrication a surface plasmon resonance sensor based on the SPP-photon transformation rather then on SPP dissipation

Magnetic light

In this paper we report on the observation of novel and highly unusual magnetic state of light. It appears that in small holes light quanta behave as small magnets so that light propagation through such holes may be affected by magnetic field. When arrays of such holes are made, magnetic light of the individual holes forms novel and highly unusual two-dimensional magnetic light material. Magnetic light may soon become a great new tool for quantum communication and computing.Comment: Submitted to Phys.Rev.Lett., 3 figure

Frontal cortex functional activity modulation impact on the stereotypic, emotional and postural behavior in rats during the interictal period of pilocarpine-induced chronic epileptogenesis

The cholinergic mechanisms role determination in epileptogenesis attracts the attention of researchers. Pilocarpine administration in rats contributes to chronic form of epileptiform activity development characterized by the presence of a pronounced acute stage and an interictal period - free from behavioral convulsive reactions. We consider the most important feature of the pilocarpine-induced seizures interictal period might be the change of various forms of nonconvulsive behavior. Attempts to investigate the animals’ behavioral reactions details during the seizure-free interictal period, as well as to determine the mechanisms of similar types of behavior formation, are interesting. The purpose of the work is to investigate the motor, stereotypic and aggressive-defensive behavior of rats throughout the interictal period of pilocarpine-induced convulsive syndrome with a frontal cortex functional activity change. It was found that the severity of non-convulsive behavioral reactions in the interictal period during pilocarpine-induced chronic seizures is mostly determined by the frontal cortex functional state. At the same time, the frontal cortex hyperactivation is an important feature of pilocarpine-induced chronic epileptogenesis.  The authors proved that when the frontal cortex is activated in rats, there is an increase in horizontal and vertical motor activity, as well as the expressiveness of emotional reactions in the “open field” test and the strengthening of the aggressive-defensive behavior. In conditions of this part of the cortex selective destruction the opposite behavioral effects are noted which confirms the important role of the frontal cortex in the interictal non-convulsive behavior formation. Observed behavioral effects during the frontal cortex functional activity modulation, according to the authors, indicate the reasonability of regulatory influences searching aiming forward this brain part to activate complex mechanisms aimed to pilocarpine-induced chronic epileptiform activity elimination

Optical control of photon tunneling through an array of nanometer scale cylindrical channels

We report first observation of photon tunneling gated by light at a different wavelength in an artificially created array of nanometer scale cylindrical channels in a thick gold film. Polarization properties of gated light provide strong proof of the enhanced nonlinear optical mixing in nanometric channels involved in the process. This suggests the possibility of building a new class of "gated" photon tunneling devices for massive parallel all-optical signal and image processing.Comment: 4 pages, 4 figure

Geometrically induced modification of surface plasmons in the optical and telecom regimes

We demonstrate that the introduction of a subwavelength periodic modulation into a metallic structure strongly modifies the guiding characteristics of the surface plasmon modes supported by the system. Moreover, it is also shown how a new type of a tightly confined surface plasmon polariton mode can be created by just milling a periodic corrugation into a metallic ridge placed on top of a metal surface

Nonlinear plasmonic amplification via dissipative soliton-plasmon resonances

In this contribution we introduce a strategy for the compensation of plasmonic losses based on a recently proposed nonlinear mechanism: the resonant interaction between surface plasmon polaritons and spatial solitons propagating in parallel along a metal/dielectric/Kerr structure. This mechanism naturally leads to the generation of a quasiparticle excitation, the so-called soliplasmon resonance. We analyze the role played by the effective nonlinear coupling inherent to this system and how this can be used to provide a mechanism of quasiresonant nonlinear excitation of surface plasmon polaritons. We will pay particular attention to the introduction of asymmetric linear gain in the Kerr medium. The unique combination of nonlinear propagation, nonlinear coupling, and gain give rise to a scenario for the excitation of long-range surface plasmon polaritons with distinguishing characteristics. The connection between plasmonic losses and soliplasmon resonances in the presence of gain will be discussed

Quality of DNA Extracted from Mouthwashes

Background A cost effective, safe and efficient method of obtaining DNA samples is essential in large scale genetic analyses. Buccal cells are an attractive source of DNA, as their collection is non-invasive and can be carried out by mail. However, little attention has been given to the quality of DNA extracted from mouthwashes. Methodology Mouthwash-derived DNA was extracted from 500 subjects participating in a genetic study of high myopia. DNA quality was investigated using two standard techniques: agarose gel electrophoresis and quantitative polymerase chain reaction (qPCR). Principal Findings Whereas the majority of mouthwash-derived DNA samples showed a single band of high molecular weight DNA by gel electrophoresis, 8.9% (95% CI: 7.1–10.7%) of samples contained only a smear of low-to-medium molecular weight, degraded DNA. The odds of DNA degradation in a subject's second mouthwash sample, given degradation of the first, was significantly greater than one (OR = 3.13; 95% CI: 1.22–7.39; Fisher's test P = 0.009), suggesting that DNA degradation was at least partially a subject-specific phenomenon. Approximately 12.4% (95% CI: 10.4–14.4%) of mouthwash-derived DNA failed to PCR amplify efficiently (using an ~200 bp microsatellite marker). However, we found there was no significant difference in amplification success rate between DNA samples judged to be degraded or non-degraded by gel electrophoresis (Fisher's test P = 0.5). Conclusions This study demonstrated that DNA degradation affects a significant minority of saline mouthwashes, and that the phenomenon is partially subject-specific. Whilst the level of degradation did not significantly prevent successful amplification of short PCR fragments, previous studies suggest that such DNA degradation would compromise more demanding applications

Взаємодія під час досудового розслідування економічних злочинів

Степанюк, Р. Л. Взаємодія під час досудового розслідування економічних злочинів [Електронний ресурс] / Р. Л. Степанюк, Д. Д. Заяць // Форум права. – 2014. – № 1. – С. 460–465 . – Режим доступу: http://nbuv.gov.ua/j-pdf/FP_index.htm_2014_1_81.pdf.Степанюк Р. Л., Заяць Д. Д. "Взаємодія під час досудового розслідування економічних злочинів." Форум права 1 (2014): 460–465.На підставі аналізу існуючих у науковій літературі точок зору встановлено, що в криміналістиці взаємодію слід розглядати у широкому, вузькому та комбінованому її розумінні, що, у свою чергу, надає можливість і обґрунтовує доцільність виділення єдиного загального визначення зазначеного поняття. Розглянуто основні структурні елементи взаємодії. З урахуванням різних підстав розроблено повну класифікацію видів та форм взаємодії у процесі розслідування злочинів. Встановлено, що важливою формою взаємодії під час розслідування економічних злочинів залишається спільна діяльність слідчого та співробітників оперативних підрозділів на початку кримінальної процесуальної діяльності. Запропоновано рекомендації застосування певних форм взаємодії з урахуванням специфіки відповідної сфери протидії економічним злочинам.Based on the analysis of existing scientific viewpoints found that forensic sense of cooperation should be considered in a broad, narrow and combined understanding that, in turn, enables and justifies the appropriateness of allocating a single common definition of the concept. There were considered the principal structural elements of the cooperation. Considering various bases a complete classification of the types and forms of cooperation in the investigation of crimes was developed. It was found that an important form of cooperation in the investigation of economic crimes is the activities of investigators and staff of the operative units at the beginning of criminal procedural activities. Authors proposed the recommendations of applying of certain forms of cooperation with respect to the specifics of the relevant area of combating economic crimes.На основании анализа существующих в научной литературе точек зрения установлено, что в криминалистическом смысле взаимодействие следует рассматривать в широком, узком и комбинированном её понимании, что, в свою очередь, даёт возможность и обосновывает целесообразность выделения единого общего определения данного понятия. Рассмотрены основные структурные элементы взаимодействия. С учетом различных оснований разработана полная классификация видов и форм взаимодействия в процессе расследования преступлений. Установлено, что важной формой взаимодействия при расследовании экономических преступлений остаётся деятельность следователей и сотрудников оперативных подразделений в начале уголовной процессуальной деятельности. Предложены рекомендации применения определенных форм взаимодействия относительно специфики соответствующей сферы противодействия экономическим преступлениям