Theoretical analysis of flux amplification by soft magnetic material in a putative biological magnetic-field receptor

Birds are endowed with a magnetic sense that allows them to detectEarth’s magnetic field and to use it for orientation. Physiological andbehavioral experiments have shown the upper beak to host amagnetoreceptor. Putative magnetoreceptive structures in the beak arenerve terminals that each contain a dozen or so of micrometer-sizedclusters of superparamagnetic nanocrystals made of magnetite/maghemiteand numerous electron-opaque platelets filled with a so farunidentified, amorphous ferric iron compound. The platelets typicallyform chainlike structures, which have been proposed to function asmagnetic flux focusers for detecting the intensity of the geomagneticfield. Here, we test that proposition from first principles and developan unconstrained model to determine the equilibrium distribution ofmagnetization along a linear chain of platelets which we assume tobehave magnetically soft and to have no magnetic remanence. Ouranalysis, which is valid for arbitrary values of the intrinsic magneticsusceptibility chi, shows that chi needs to be much greater than unityto amplify the external field by two orders of magnitude in a chain ofplatelets. However, the high amplification is confined to the centralregion of the chain and subsides quadratically toward the ends of thechain. For large values of chi, the possibility opens up of realizingmagnetoreceptor mechanisms on the basis of attraction forces betweenadjacent platelets in a linear chain. The force in the central region ofthe chain may amount to several pN, which would be sufficient to convertmagnetic input energy into mechanical output energy. The strikingfeature of an ensemble of platelets is its ability to organize intotightly spaced chains under the action of an external field of givenstrength. We discuss how this property can be exploited for amagnetoreception mechanism

Almost Periodic and Asymptotically Almost Periodic Solutions of Liénard Equations

The aim of this paper is to study the almost periodic and asymptotically almost periodic solutions on (0,+1) of the Li´enard equation x′′ + f(x)x′ + g(x) = F(t), where F : T ! R (T = R+ or R) is an almost periodic or asymptotically almost periodic function and g : (a, b) ! R is a strictly decreasing function. We study also this problem for the vectorial Li´enard equation. We analyze this problem in the framework of general non-autonomous dynamical systems (cocycles). We apply the general results obtained in our early papers [3, 7] to prove the existence of almost periodic (almost automorphic, recurrent, pseudo recurrent) and asymptotically almost periodic (asymptotically almost automorphic, asymptotically recurrent, asymptotically pseudo recurrent) solutions of Li´enard equations (both scalar and vectorial)

Prompt emission from tidal disruptions of white dwarfs by intermediate mass black holes

We present a qualitative picture of prompt emission from tidal disruptions of white dwarfs (WD) by intermediate mass black holes (IMBH). The smaller size of an IMBH compared to a supermassive black hole and a smaller tidal radius of a WD disruption lead to a very fast event with high peak luminosity. Magnetic field is generated in situ following the tidal disruption, which leads to effective accretion. Since large-scale magnetic field is also produced, geometrically thick super-Eddington inflow leads to a relativistic jet. The dense jet possesses a photosphere, which emits quasi-thermal radiation in soft X-rays. The source can be classified as a long low-luminosity gamma-ray burst (ll-GRB). Tidal compression of a WD causes nuclear ignition, which is observable as an accompanying supernova. We suggest that GRB060218 and SN2006aj is such a pair of ll-GRB and supernova. We argue that in a flux-limited sample the disruptions of WDs by IMBHs are more frequent then the disruptions of other stars by IMBHs

Pathological features of the lungs and liver of piglets under conditions of constant vaccination of livestock against circovirus infection

The pathogenicity of PCV 2 in the body of vaccinated piglets was studied based on the results of pathomorphological changes in the lungs and liver of animals. The work was carried out on commercial piglets vaccinated with the vaccine Ingelvak CircoFLEX (Germany) against circovirus. The work used clinical, zootechnical, enzyme immunoassay and pathomorphological research methods. It has been established that under the conditions of ongoing vaccination of piglets against PCV2, 30.3% of piglets still do not have virus-neutralizing antibodies. The main reason for the culling of animals are circovirus diseases that have respiratory clinical signs, as well as signs of multisystem wasting syndrome, determining the safety of the livestock at the level of 68.05%, the average live weight of 1 head at the moment of its transfer for fattening is 40.44±0.78 kg, and the average daily gain in live weight is 346.00±9.18 g. At autopsy, sick piglets reveal an increase in the lungs and liver, and the signs of inflammation in them, as a result of circulatory disorders, damage to the lymphoid tissue, the development of dystrophic and necrotic changes. The results of the research suggest that in order to increase the efficiency of the formation of post-vaccination immunity, specific medical preparations can be used to stimulate the immune response of the body, as well as to enhance the resistance of the lymphoid tissue of the lungs and liver in animals.The pathogenicity of PCV 2 in the body of vaccinated piglets was studied based on the results of pathomorphological changes in the lungs and liver of animals. The work was carried out on commercial piglets vaccinated with the vaccine Ingelvak CircoFLEX (Germany) against circovirus. The work used clinical, zootechnical, enzyme immunoassay and pathomorphological research methods. It has been established that under the conditions of ongoing vaccination of piglets against PCV2, 30.3% of piglets still do not have virus-neutralizing antibodies. The main reason for the culling of animals are circovirus diseases that have respiratory clinical signs, as well as signs of multisystem wasting syndrome, determining the safety of the livestock at the level of 68.05%, the average live weight of 1 head at the moment of its transfer for fattening is 40.44±0.78 kg, and the average daily gain in live weight is 346.00±9.18 g. At autopsy, sick piglets reveal an increase in the lungs and liver, and the signs of inflammation in them, as a result of circulatory disorders, damage to the lymphoid tissue, the development of dystrophic and necrotic changes. The results of the research suggest that in order to increase the efficiency of the formation of post-vaccination immunity, specific medical preparations can be used to stimulate the immune response of the body, as well as to enhance the resistance of the lymphoid tissue of the lungs and liver in animals

Critical Dynamics of Self-Organizing Eulerian Walkers

The model of self-organizing Eulerian walkers is numerically investigated on the square lattice. The critical exponents for the distribution of a number of steps ($\tau_l$) and visited sites ($\tau_s$) characterizing the process of transformation from one recurrent configuration to another are calculated using the finite-size scaling analysis. Two different kinds of dynamical rules are considered. The results of simulations show that both the versions of the model belong to the same class of universality with the critical exponents $\tau_l=\tau_s=1.75\pm 0.1$.Comment: 3 pages, 4 Postscript figures, RevTeX, additional information available at http://thsun1.jinr.dubna.su/~shche

Study (301)-(000) D2O band in 10200 - 10450 cm-1 spectral region

Measurements of D2O absorption spectra in the visible spectral region near 0.98 μm are performed using FT-spectrometer IFS-125M and Light-emitting diode (LED) as source of radiation. Water vapor spectrum has been obtained by averaging over 17136 scans recorded at 24 m optical path length, temperature 24 С and pressure of sample 27 mBar. Due to strong emission of LED source it was possible to achieve signal-to-noise ratio about 104 and to record weak lines with intensities of 6 10-27 cm/molecule. Comparisons with results of early works are made. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Effect of electric field on the photoluminescence of polymer-inorganic nanoparticles composites

We report on the effect of electric field on the photoluminescence, PL, from a composite consisting of a conjugated polymer mixed with zinc oxide nanoparticles. We have found that in the absence of electric field PL emission from the composite film has two maxima in the blue and green-yellow regions. Application of a voltage bias to planar gold electrodes suppresses the green-yellow emission and shifts the only PL emission maximum towards the blue region. Current-voltage characteristics of the polymer-nanoparticles composite exhibit the non-linear behavior typical of non-homogeneous polymer-inorganic structures. Generation of excited states in the composite structure implies the presence of several radiative recombination mechanisms including formation of polymer-nanoparticle complexes including exciplex states and charge transfer between the polymer and nanoparticle that can be controlled by an electric field.Comment: 5 pages, 5 figures. accepted for publication in Solid State Communication

The Problems of the Replacement of Alternative Penalties Taking into Account the Implementation of International Standards: Case of Some Post-Soviet Countries

International standards for the treatment of convicts without isolation from society contain the world experience of humanism in the execution of punishments and the development of the correctional system of all the countries in the world, concerning Russia and the countries of the former Soviet Union, they are adopted and implemented relatively recently. Today not all international standards have found their consolidation in the sectoral legislation of Russia and the CIS and Baltic countries. The execution of punishments is one of the most detailed regulated processes from the point of view of international regulation, as for the classification of the state as democratic, largely affects the compliance of its sectoral legislation in the penitentiary sphere with international standards. The aim of the study is to determine the features of the procedure for the replacement of alternative penalties, taking into account the implementation of international standards in some post-Soviet countries.     Keywords: international standards; alternative punishments; court; Prosecutor’s office; replacement of punishments

Морфология и экологические особенности Sparganium × longifolium (Typhaceae) в центре Европейской части России

The increasing impact of anthropogenic factors and climate change affect the growth of a number of taxa of hybrid nature. These taxa are widespread among various taxonomic groups of aquatic and semi-aquatic plants. The genus Sparganium L. В is not an exception. In that regard, the aim of this study is to conduct biomorphological investigation of Sparganium × longifolium Turcz. ex Ledeb., evaluate qualitative and quantitative criteria for the hybrid similarities and differences with its parental species, as well as to analyze data on its habitat characteristics. Samples were collected in 2014–2016 from waterbodies in European Russia (Tver and Yaroslavl oblasts). In the study on biomorphology of S. × longifolium we used live and fixed materials, as well as herbarium funds of IBIW, MXA and MW. To establish and specify taxonomic features of the hybrid under study, indicating to its similarity with a certain ancestral species, our data on the morphology and ecology of S. emersum Rehm. and S. gramineum Georgi. are used. During field studies, the type of water object where the hybrid was detected, ecological characteristics of its habitat (type of soil, depth, water temperature and pH) are determined; the list of taxa which enter into the cenosis composition is compiled. The biomorphological investigation of S. × longifolium shows that by life form this hybrid, as well as its parental species, is a vegetative-mobile evidently-polycentric annual or biennial plant of vegetative origin with a racemose root system. The following should be attributed to the characteristic features justifying the hybrid origin of S. × longifolium: 1) a wider, slightly carinated lamina (as in S. emersum); 2) a branched inflorescence (as in S. gramineum); 3) the lower covering leaf of inflorescence, often exceeding the total length of the latter; 4) fruits with a straight (as in S. emersum) as well as bent (as in S. gramineum) style. Interestingly, some populations of S. × longifolium are rich in terate forms that can be explained by back crossing with one of the parental species or pleiotropic mutation(s). It is established that S. × longifolium is not widespread in European Russia, is a typically freshwater species, occurring in the littoral zone of mesotrophic and dystrophic waterbodies (usually in lakes of glacier origin). At present, its appearance in lake ecosystems is due to accelerated eutrophication caused by increasing human activities. Perhaps earlier this hybrid formation occurred in peripheral zones of the range of S. gramineum under cyclic climate changes. Observations suggest that S. × longifolium exceeds S. gramineum in ecological potential. At the same time, habitat features of the latter have an effect on the hybrid’s distribution potential (limitation of habitat spectrum), which is hardly exceeds S. emersum in its ecological and coenotic characteristics. 154   На основе современных подходов к анализу жизненных форм рассмотрена морфология вегетативной и генеративной сферы Sparangium × longifolium Turcz. ex Ledeb. (S. emersum Rehm. × S. gramineum Georgi). По жизненной форме S. × longifolium, как и его родительские виды, представляет собой вегетативно-подвижный явнополицентрический малолетник вегетативного происхождения с кистевидной корневой системой. В работе установлен промежуточный характер конкретных признаков гибрида, либо смещение того или иного признака в сторону одного из родительских видов. К характерным особенностям, подтверждающим гибридное происхождение S. × longifolium, следует отнести: 1) наличие более широкой, слегка килеватой листовой пластинки (как у S. emersum); 2) наличие разветвленного соцветия (как у S. gramineum); 3) нижний кроющий лист соцветия, часто превышающий общую длину последнего; 4) наличие плодов как с прямым (как у S. emersum), так и с загнутым (как у S. gramineum) столбиком. Отдельные популяции S. × longifolium изобилуют тератными формами, которые могут быть объяснены наличием возвратного скрещивания, либо мутации(й) с плейотропным проявлением. Анализ пыльцы гибрида на жизнеспособность показал преобладание стерильной пыльцы над фертильной. Установлено, что S. × longifolium – малораспространенный на территории Европейской части России – типично пресноводный вид, встречающийся в прибрежной зоне мезотрофных и дистрофных водных объектов (обычно в озерах ледникового происхождения). Появление популяций гибрида в озерах обусловлено их стремительной эвтрофикацией в результате антропогенной деятельности. Ранее образование этого гибрида, вероятно, происходило в периферийных частях ареала S. gramineum при циклических изменениях климата. Вместе с тем, особенности местообитания последнего накладывают «отпечаток» на потенциал распространения гибрида (ограниченность спектра местообитаний), который вряд ли может превзойти по своим эколого-ценотическим характеристикам S. emersum.&nbsp