Fabrication of Polymeric Multimode Waveguides for Application in the Local Area Network and Optical Interconnects.

We report the fabrication of multimode polymeric waveguides using spin coating, photolithography, and reactive ion etching. Different layer structures have been used, e.g., a UV curable resin is used as a core layer and PMMA as a lower and upper cladding. The layer systems can be spun with good uniformity with thicknesses matching multimode fiber dimensions, and smooth waveguide side-walls have been obtained after etching. The measured performance of these waveguides demonstrates that low-loss waveguides can be fabricated cheaply. The waveguides are used in the realization of novel compact multimode power splitters and star couplers

Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses

Copyright: © 2015 Sudhakar et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNeurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it.Peer reviewedFinal Published versio

Ins and Outs of Cerebellar Modules

The modular concept of cerebellar connections has been advocated in the lifetime work of Jan Voogd. In this concept, a cerebellar module is defined as the conglomerate of one or multiple and non-adjacent, parasagittally arranged zones of Purkinje cells, their specific projection to a well-defined region of the cerebellar nuclei, and the climbing fiber input to these zones by a well-defined region of the inferior olivary complex. The modular organization of these olivo-cortico-nuclear connections is further exemplified by matching reciprocal connections between inferior olive and cerebellar nuclei. Because the different regions of the cerebellar nuclei show highly specific output patterns, cerebellar modules have been suggested to constitute functional entities. This idea is strengthened by the observation that anatomically defined modules adhere to the distribution of chemical markers in the cerebellar cortex suggesting that modules not only differ in their input and output relations but also may differ in operational capabilities. Here, I will briefly review some recent data on the establishment of cerebellar modules in rats. Furthermore, some evidence will be shown suggesting that the other main afferent system (i.e., mossy fibers), at least to some extent, also adheres to the modular organization. Finally, using retrograde transneuronal tracing with rabies virus, some evidence will be provided that several cerebellar modules may be involved in the control of individual muscles

Pelatihan dan Pendampingan Pembelajaran Daring Berbasis Moodle untuk Guru Fisika SMA di Kabupaten Malang Selama Masa Pandemi Covid-19

Dampak dari pendemi covid-19 memaksa setiap sekolah mewajibkan guru dan siswanya melakukan pembelajaran secara daring dari rumah. Hal tersebut membuat guru dan siswa dalam waktu yang singkat harus mempersiapkan seluruh vasilitas pendukung pembelajaran. Sedangkan di Kabupaten Malang, para guru fisika masih belum begitu akrab dengan pembelajaran daring, maka pendampingan dan pelatihan pembelajaran daring dengan memanfaatkan moodle sangat dibutuhkan. Kegiatan diawali dengan studi literatur dan lapangan, perencanaan, pemberian materi, demosntrasi dan praktek dan diakhiri dengan kegiatan evaluasi. Untuk mengetahui keberhasilan program, kami menyebarkan kueisioner (n = 13 item) kepada seluruh peserta tentang persepsi terhadap pembelajaran menggunakan moodle dan memantau perkembangan pemahaman guru melalui moodle yang telah dikembangkan. Guru fisika didampingi dan dilatih untuk membuat pembelajaran daring melalui moodle dan variasi model moodle yang sudah pernah diperoleh. Peserta pelatihan dan pendampingan yang diselenggarakan secara daring berjumlah 40 guru fisika di wilayah Kabupaten Malang yang meliputi 34 orang guru fisika SMA dan 6 orang guru fisika MA. Walaupun kehadiran guru tidak bersamaan masuk room meet, tetapi setiap guru selalu masuk setiap hari. Namun, yang aktif mengerjakan pembuatan moodle hanya 25 orang guru yaitu 24 orang guru SMA dan 1 orang guru MA. Peserta yang membuat moodle tersebut bervariasi ada yang hanya membuat Assignment untuk materi dinamika, sampai ada yang lengkap membuat assignment, quiz, dan file untuk materi mekanika, dinamika, usaha dan energi, serta impuls dan momentum. Berdasarkan respon peserta pada angket terkait pelatihan dan pendampingan penyusunan moodle didapatkan 75,19% peserta merespon baik pembelajaran dengan moodle

Fabrication of Polymeric Multimode Waveguides for Application in the Local Area Network and Optical Interconnects

We report the fabrication of multimode polymeric waveguides using spin coating, photolithography, and reactive ion etching. Different layer structures have been used, e.g., a UV curable resin is used as a core layer and PMMA as a lower and upper cladding. The layer systems can be spun with good uniformity with thicknesses matching multimode fiber dimensions, and smooth waveguide side-walls have been obtained after etching. The measured performance of these waveguides demonstrates that low-loss waveguides can be fabricated cheaply. The waveguides are used in the realization of novel compact multimode power splitters and star couplers