Initial results from a realtime FRB search with the GBT

We present the data analysis pipeline, commissioning observations and initial results from the GREENBURST fast radio burst (FRB) detection system on the Robert C. Byrd Green Bank Telescope (GBT) previously described by Surnis et al. which uses the 21~cm receiver observing commensally with other projects. The pipeline makes use of a state-of-the-art deep learning classifier to winnow down the very large number of false positive single-pulse candidates that mostly result from radio frequency interference. In our observations totalling 156.5 days so far, we have detected individual pulses from 20 known radio pulsars which provide an excellent verification of the system performance. We also demonstrate, through blind injection analyses, that our pipeline is complete down to a signal-to-noise threshold of 12. Depending on the observing mode, this translates to peak flux sensitivities in the range 0.14--0.89~Jy. Although no FRBs have been detected to date, we have used our results to update the analysis of Lawrence et al. to constrain the FRB all-sky rate to be $1140^{+200}_{-180}$ per day above a peak flux density of 1~Jy. We also constrain the source count index $\alpha=0.83\pm0.06$ which indicates that the source count distribution is substantially flatter than expected from a Euclidean distribution of standard candles (where $\alpha=1.5$). We discuss this result in the context of the FRB redshift and luminosity distributions. Finally, we make predictions for detection rates with GREENBURST, as well as other ongoing and planned FRB experiments.Comment: 9 pages, 7 figures, submitted to MNRA

IMPLEMENTATION OF RAINBOW TECHNOLOGY USING GRAY SCALE

ABSTRACT Storing audio, video, text, image etc. Data on a piece of paper instead of using CD's & DVD's. With the advent in the techniques of compression and encryption it will become possible to store data equivalent to CD's or DVD's on a piece of paper in near future. After reading data we need to scale down their sampling values between 0 and 1. We will construct gray scale image from this values. So now data in the form of image can be distributed using measures like printouts. The paper can then be read through a normal scanning and the contents are decoded from matrix to reconstruct the sampled values which can be viewed or played. Though we are not able completely reconstruct noise free original data, we firmly believe that this will be important for future advancement of this idea. This extremely low cost technology will drastically reduce the cost of the storage and will provide high-speed storage as well. There are many advantages of storing data on paper such as biodegradability, cost, duplication, data transfer, speed, size, and security

Microbiological and clinical evaluation of efficacy of locally delivered tetracycline in conjunction with scaling and root planning

Introduction: Chronic periodontitis is an infectious disease which is multifactorial in etiology. The red complex bacteria have an enzyme capable of hydrolyzing the synthetic trypsin substrate, N-benzoyl-DL-arginine-2-napthylamide (BANA). Tetracycline as a bacteriostatic agent is used in the treatment of periodontitis. Objective: The aim of this study was to evaluate clinically and microbiologically the efficacy of tetracycline fibers in conjunction with scaling and root planning in chronic periodontitis patients. Methodology: A Split mouth clinical and microbiological randomized control study was done to compare the clinical effects of subgingivally delivered antimicrobial bioabsorbable controlled release 2 mg tetracycline fibers as an adjunct to scaling and root planning on one side and comparing the other side treated only with scaling and root planning only. Result: Showed both scaling and root planning and the use of tetracycline an adjunct with scaling and root planning are equally effective. Conclusion: It can be concluded that Scaling and root planing (SRP) with or without use of adjunct local drug delivery agent like tetracycline is effective in treating chronic periodontitis

Chromatin Accessibility and Transcriptional Differences in Human Stem Cell-Derived Early-Stage Retinal Organoids

Retinogenesis involves the specification of retinal cell types during early vertebrate development. While model organisms have been critical for determining the role of dynamic chromatin and cell-type specific transcriptional networks during this process, an enhanced understanding of the developing human retina has been more elusive due to the requirement for human fetal tissue. Pluripotent stem cell (PSC) derived retinal organoids offer an experimentally accessible solution for investigating the developing human retina. To investigate cellular and molecular changes in developing early retinal organoids, we developed SIX6-GFP and VSX2-tdTomato (or VSX2-h2b-mRuby3) dual fluorescent reporters. When differentiated as 3D organoids these expressed GFP at day 15 and tdTomato (or mRuby3) at day 25, respectively. This enabled us to explore transcriptional and chromatin related changes using RNA-seq and ATAC-seq from pluripotency through early retina specification. Pathway analysis of developing organoids revealed a stepwise loss of pluripotency, while optic vesicle and retina pathways became progressively more prevalent. Correlating gene transcription with chromatin accessibility in early eye field development showed that retinal cells underwent a clear change in chromatin landscape, as well as gene expression profiles. While each dataset alone provided valuable information, considering both in parallel provided an informative glimpse into the molecular nature eye development

Human retinal ganglion cell neurons generated by synchronous BMP inhibition and transcription factor mediated reprogramming

Abstract In optic neuropathies, including glaucoma, retinal ganglion cells (RGCs) die. Cell transplantation and endogenous regeneration offer strategies for retinal repair, however, developmental programs required for this to succeed are incompletely understood. To address this, we explored cellular reprogramming with transcription factor (TF) regulators of RGC development which were integrated into human pluripotent stem cells (PSCs) as inducible gene cassettes. When the pioneer factor NEUROG2 was combined with RGC-expressed TFs (ATOH7, ISL1, and POU4F2) some conversion was observed and when pre-patterned by BMP inhibition, RGC-like induced neurons (RGC-iNs) were generated with high efficiency in just under a week. These exhibited transcriptional profiles that were reminiscent of RGCs and exhibited electrophysiological properties, including AMPA-mediated synaptic transmission. Additionally, we demonstrated that small molecule inhibitors of DLK/LZK and GCK-IV can block neuronal death in two pharmacological axon injury models. Combining developmental patterning with RGC-specific TFs thus provided valuable insight into strategies for cell replacement and neuroprotection