Coulomb interaction and electron-hole asymmetry in cyclotron resonance of bilayer graphene in high magnetic field

Inter-Landau-level transitions in the bilayer graphene at high perpendicular magnetic field at the filling-factor v<<1 have been studied. The next-nearest-neighbor transitions, energy difference between dimer and non-dimer sites and layer asymmetry are included. The influence of Coulomb interaction is taken into account. The magnetoplasmon excitations in bilayer graphene at small momenta are considered in the frame of the Hartree-Fock approximation. It is shown that asymmetry in cyclotron resonance of clean bilayer graphene depends on magnetic field. At lower magnetic fields the energy splitting in the spectrum is due to electron-hole one-particle asymmetry, at higher magnetic fields the energy splitting in the spectrum is due to Coulomb interaction. For the fullsymmetric case with half-filled zero-energy levels the energy splitting proportional to the energy of Coulomb interaction is found both for bilayer and monolayer graphene.Comment: 6 pages, 2 figure

Laser Beam Characterization by Imaging for Product Inspection

This thesis discusses the design and the realization of a Beam Propagation Analyzer apparatus and the application of laser beams in surface characterization. Most of this work has been performed at the University of Erlangen-Nürnberg, Chair of Photonics Technologies (Germany). Today laser beams are widely used in a large number of industrial applications. Mechanical Machining, Electronics Industries, Communication Engineering and Medical Application are some areas in which the laser technologies play a key role. The design of optical system is treated with powerful simulation software but it requires at the same time a good knowledge of basic rules of Optics. These beam propagation and transformation can be defined by two critical parameters: the beam waist (the smallest beam radius achieved in the beam trajectory) and the divergence angle (the ratio at which the beam enlarges far away from the waist). These parameters are strongly related and they are important indicators of the beam quality. The beam quality can be measured with an apparatus composed by a beam profiler (instrument able to measure the intensity profile of the beam) and a translation stage that permits the measurement of the beam intensity at different positions. Such a type of apparatus has been realized. The apparatus has been designed and realized with commercial elements, the hardware interacts with the laser beam and PC software controls the image acquisitions and analyzes the data. Laser beams are also widely used in surface characterization. A novel method, based on the speckle effect and normally applied in roughness characterization of metallic surfaces, is tested on Carrara marble stones to investigate a possible new field of applications

QUALITY-PERCEIVED MULTIPLE LABEL-SWITCHED PATHS FOR ACHIEVING ULTRA-RELIABLE WI-FI FOR INDUSTRIAL IOT DEPLOYMENTS

Operating within an environment that incorporates technologies based on Multiprotocol Label Switching (MPLS) and the Label Distribution Protocol (LDP) to provide an ultra-reliable wireless backhaul service supporting large Internet of Things (IoT) and Industrial IoT (IIoT) environments (comprising, for example, many hundreds of radio devices), techniques are presented herein that support a mechanism to implement quality-perceived multiple label-switched paths (LSP)s that can perform replication according to path quality. Aspects of the presented techniques leverage a replication strategy, that is defined on both a client and a Network Appliance that defines how replication should be performed with preconditions, replication should be stopped when the preconditions are not met, or replication should be recovered when a precondition is met. According to aspects of the presented techniques, when a strategic precondition is met or not met, the corresponding LSP state is changed to pending or recovered (respectively) instead of being torn down or being rebuilt

Electrical activity regulates dendritic reorganization in ganglion cells after neonatal retinal lesion in the cat

During the first month of postnatal life, the dendritic arborizations of cat retinal ganglion cells continue to develop and undergo a substantial remodeling. Mechanical and pharmacological interferences with the normal development induce, during this period of time, substantial modifications in ganglion cell morphology. Specifically, the degeneration of those neurons whose axons were severed by a neonatal retinal lesion leads to a zone depleted of ganglion cells. Neurons at the border of the depleted area develop an abnormal elongation of the dendritic trees toward the empty space. In the present paper, we report data showing that this dendritic reorganization can be prevented by blocking the electrical activity with repeated tetrodotoxin injections into the eye during the whole critical period. Our analysis was performed on neurons filled with horseradish peroxidase

Long-term treatment of the developing retina with the metabotropic glutamate agonist APB induces long-term changes in the stratification of retinal ganglion cell dendrites

The gradual restriction of initially multistratified retinal ganglion cell (RGC) dendrites into ON and OFF sublaminae of the inner plexiform layer (IPL) can be effectively blocked by treating the developing retina with 2-amino-4-phosphonobutyrate (APB), the metabotropic glutamate agonist, or by light deprivation. Previous studies have focused on the short-term consequences of such manipulations, so the long-term effects of arresting dendritic stratification on the structural development of RGCs are as yet unknown. In the present study, we have addressed this issue by performing a morphological analysis of alpha RGCs labeled by retrograde transport of horseradish peroxidase injected into the dorsal lateral geniculate nucleus of adult cats that received monocular injections of APB from postnatal (P) day 2 until P30. A large proportion of the alpha cells in the APB-treated eye (44%) were found to have multistratified dendrites that terminated in both the ON and OFF sublaminae of the IPL. The dendritic arborization pattern in the sublaminae of the IPL of these cells was asymmetric, showing a variety of forms. Immunolabeling of retinal cross-sections showed that mGLUR6 receptors appeared normal in density and location, while qualitative observation suggested an increase in the axonal arborization of rod bipolar cells. These findings indicate that long-term treatment of the neonatal retina with APB induces a long- lasting structural reorganization in retinal circuitry that most likely accounts for some of the previously described changes in the functional properties of RGCs

Analysis of pharmacologically isolated components of the ERG

AbstractAn harmonic analysis was applied to the electroretinogram (ERG) measured in intact cat eyes in control conditions and after pharmacological isolation of the components attributed to photoreceptors (PIII) and bipolar neurons (PII). The frequency response curves obtained in various conditions showed that the bandwidth of the PII component extends over a range of stimulus frequencies higher than the bandwidth of PIII. The enhancement of the PII response to stimuli of high temporal frequency suggests the presence of a frequency dependent gain control located either pre- and/or post-synaptically in the transmission line between the phototransductive cascade and bipolar neurons. A possible role of these processes is to enhance relevant visual information whilst selectively attenuating low frequency signals originating in the transductive cascade

Mahabbah menurut Buya Nursamad Kamba

Keterkaitan dengan fenomena yang sering terjadi saat ini krisis tanpa dilandasi atas rasa cinta yaitu apabila ketika hendak melakukan sebuah aktivitas pekerjaan, mereka hanya akan taat apabila telah mendapatkan pahala dari-Nya bukan berdasarkan keinginan yang tulus dari hati, ini sering terjadi pada era saat ini. Sebagian mungkin tidak mengetahui dan tidak mengenal tentang pentingnya menghadirkan mahabbah dalam melakukan sesuatu yang seharusnya aktivitas itu dikerjakan semata-mata karna Allah, tidak dibarengi oleh kepentingan yang lain. Jika meyakini itu sebagai bentuk mahabbah maka akan terasa lebih bernilai dan indah menjalaninya. Penelitian ini dilakukan untuk membahas mahabbah menurut Buya Nursamad Kamba. Adapun tujuan penelitian ini untuk mengetahui mahabbah menurut Buya Nursamad Kamba Juga untuk mengetahui karakteristik mahabbah menurut Buya Nursamad Kamba. Penelitian ini menggunakan pendekatan kualitatif dengan menerapkan metode deskriptif-analitis. Sumber primer pada penelitian ini adalah buku yang berjudul “Mencintai Allah Secara Merdeka” dan “Tuhan Maha Asik” dengan teori mahabbah menurut Imam al-Ghazali. Penilitian ini menyimpulkan bahwa berdasarkan pandangan Buya Nursamad Kamba konsep mahabbah yang diajarkanya adalah dengan cara ma’rifat karna pengetahuan bisa mengantarkan untuk lebih dekat kepada-Nya sejalan sengan pendapat Imam al-Ghazali yaitu meliha cinta itu merupakan buah dari suatu pengetahuan, yang mana akan melahirkan cinta pada-Nya. sebab cinta ini tidak akan hadir tanpa pengetahuan dan juga pemahaman. Karakteristik mahabbah menurut Buya Nursamad Kamba adalah dengan cara mencapai ma’rifat dengan jalan ber-mahabbah, bentuk syukur yang dirasakan dari doa yang tersirat dari doa bangun tidur, secara otomatis mengantarkan kepada cinta yang murni kepada Ilahi dimana setiap cinta itu menjadikan seluruh aktivitas yang dikerjakan dengan suka rela dan senang hati. Maka dari itu, sebagai hamba Allah harusnya dalam melakukan segala aktivitas itu, dilakukan dengan tulus dan menghadirkan rasa mahabbah (cinta) pada saat melewatinya, agar kehidupan yang dijalani terasa lebih bermakna dan penuh rasa syukur

The impact of Basic Fibroblast Growth Factor on Photoreceptor function and morphology

To assess the impact of basic fibroblast growth factor (bFGF) on photoreceptor function and morphology. METHODS: Impact was assessed in two models. In one, the endogenous expression of bFGF in photoreceptors was raised by sectioning one optic nerve of rats 3 to 4 weeks before study. In the other, bFGF was injected into the vitreous chamber in rats and cats. Retinal function was assessed from the electroretinogram (ERG), and retinal morphology was studied using DNA dyes, immunolabeling, and in situ hybridization. RESULTS: In both models of bFGF upregulation, the ERG b-wave was suppressed over a wide stimulus range and in light- and dark-adapted conditions. The a-wave was not suppressed by either procedure and at the brightest intensities was enhanced by both procedures. In nerve-sectioned eyes, outer retina appeared normal histologically, but levels of bFGF protein in the inner and outer nuclear layers were raised, whereas bFGF mRNA levels remained unchanged. In both models, levels of synaptophysin in the outer plexiform layer and of cytochrome oxidase in inner segments were raised in association with increases in bFGF protein levels. CONCLUSIONS: bFGF increased the ability of photoreceptors to respond to light but attenuated the transmission of this response to inner retinal cells, presumably by blocking the photoreceptor-bipolar synapse. If the expression of bFGF protein is upregulated in human photoreceptor dystrophies, it may contribute a reversible component to the loss of vision. The relationship between these actions of bFGF and its ability to protect photoreceptors from stress remains to be established