24 research outputs found
Physiological roles and regulation of the cryptic prophage-encoded small protein DicB and small RNA DicF in Escherichia coli
No full textBacterial adaptation to stress conditions is vital for their survival in different environments. In the past decade, the important roles that small RNAs (sRNAs) and small proteins perform in regulating the stress response in bacteria has become evident. While the roles of numerous sRNAs and small proteins encoded on the bacterial core genome have been characterized, very few that are phage or prophage-encoded have been studied. This dissertation describes the roles and regulation of the sRNA DicF and small protein DicB encoded on the Qin cryptic prophage of Escherichia coli K12. Bacterial genomes harbor cryptic prophages that have lost genes required for induction, excision from host chromosomes, or production of phage progeny. DicB and DicF are encoded on the dicBF operon, which is located in the immunity region of the cryptic prophage Qin. DicB and DicF have previously been implicated in inhibiting cell division of the host bacterium. In this study, we show that the small protein DicB protects the host cells from phage infection. DicB specifically inhibits infection by λ and other phages that use ManYZ inner membrane proteins to inject their DNA into the host cell. DicB also inhibits the canonical function of ManYZ, which is mannose sugar transport. We demonstrated that the previously known interaction between DicB and MinC, a host protein involved in proper positioning of the Z ring during cell division, is necessary for the DicB-dependent phenotypes involving ManYZ identified in this study. The sRNA DicF is widely conserved is many E. coli strains and inhibits ftsZ mRNA translation in E. coli. In this study, we establish the mechanism of this regulation by characterizing the base pairing interaction between DicF and ftsZ, and delineate the roles of other host factors involved in this regulation. Additionally, we identify new mRNA targets of the sRNA DicF, that are primarily involved in host cell metabolism. The final part of this thesis work describes the genetic mechanisms defining the regulation of the dicBF operon. The dicBF operon is constantly repressed under laboratory conditions by the repressor DicA. In this work, we identified that the protein Rem impairs DicA repression of the dicBF operon and is the antirepressor of DicA. We show that Rem induces expression of dicB and dicF, which leads to the concomitant cell filamentation phenotype as DicB and DicF are cell division inhibitors. In the absence of the dicBF gene products, the promoter of the dicBF operon was found to undergo spontaneous induction in a subset of cells, reminiscent of the λ phage bistable genetic switch. Lastly, urea and high temperature were identified as strong inducers of the dicBF promoter in strains deleted for the dicBF operon. Our results suggest that expression of the dicBF operon is regulated in multiple ways in E. coli K12, indicative of the complex relationship that exists between the host cell and cryptic prophages.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2023-05-01The student, Preethi Narayani Thattai Ragunathan, accepted the attached license on 2020-12-22 at 15:01.The student, Preethi Narayani Thattai Ragunathan, submitted this Dissertation for approval on 2020-12-22 at 16:38.This Dissertation was approved for publication on 2020-12-23 at 13:10.DSpace SAF Submission Ingestion Package generated from Vireo submission #16136 on 2021-09-16 at 17:01:29Made available in DSpace on 2021-09-17T02:34:10Z (GMT). No. of bitstreams: 2
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Previous issue date: 2020-12-23Embargo set by: Seth Robbins for item 118462
Lift date: 2023-09-17T02:34:57Z
Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemAuthor requested U of Illinois access only (OA after 2yrs) in Vireo ETD systemU of I Onl
Segmentation of Carpal Bones: Based on Statistical Shape Models using Spherical Harmonics
No full textA study has been conducted on the application of Spherical Harmonics based Statistical Shape Modelling for Image Segmentation. This study is focused on the segmentation of Wrist bones using the above mentioned technique.Mechanical Engineering | BioMechanical Desig
Effect of γ-aminopropyltriethoxy silane (γ-APS) coupling agent on mechanical and morphological properties of high density polyethylene (HDPE)/acrylonitrile butadiene rubber (NBR)/palm pressed fibre (PPF) composites
No full textIsolation and Characterization of Collagen from Cephalothorax of Penaeus
No full textThis study aimed to examine the yield and properties of collagen protein isolated from the cephalothorax of Penaeus monodon. Collagen underwent analysis using gel electrophoresis. The results indicated that collagen comprises α1 and α2 subunits with corresponding average molecular weights. The investigation into collagen solubility revealed that, in the presence of NaCl, collagen exhibited the greatest relative solubility at 2% NaCl (80.20 ± 4.95%). Conversely, solubility diminished with elevated NaCl concentrations. Collagen had the maximum relative solubility at pH 3 (91.32 ± 5.14%), with solubility diminishing at elevated pH levels. FT-IR spectroscopy was employed to contrast collagen with a model molecule. Five wavenumbers in the spectrum for model collagen were identified: Amide A (3,406–3,421 cm⁻¹), Amide B (2,916–2,940 cm⁻¹), Amide I (1,639–1,640 cm⁻¹), Amide II (1,539–1,570 cm⁻¹), and Amide III (1,234–1,250 cm⁻¹). The cytotoxic impact on 3T3-L1 cells was evaluated
Effect of polypropylene maleic anhydride (PPMAH) on mechanical and morphological properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr)/empty fruit bunch (EFB) composites
No full textHistological Analysis of the Gill and Swim Bladder of Hong Kong Catfish (Clarias fuscus)
No full textThis research aims to characterize the histological features of the gills and swim bladder of adult Hong Kong catfish (Clarias fuscus) weighing an average of 650 g and 40 cm in length. The organs (gills and swim bladders) were dissected and fixed for 48 hours in 10% neutral buffered formalin (NBF) fixative. The organs were then subjected to standard procedures: paraffin embedding, microtome sectioning, staining and mounting, followed by observation under a Carl Zeiss binocular compound microscope. The Gills of Clarias fuscus showed normal primary and secondary gill lamellae. A significant number of lymphocytes infiltrated the gill lamellae. The swim bladder tissues of Clarias fuscus displayed no inflammation, edema or necrosis in the lateral body wall and coelomic cavity. The columnar epithelium has expanded, folded, and filled the swim bladder\u27s lumen entirely. The data acquired can be used to establish a baseline for healthy Hong Kong catfish, aiding researchers in understanding how gill and swim bladder respond to diseases and environmental factors
Riboflavin Enrichment of Oziotelphusa senex senex Meat Via Microbial Biofortification Using Bacillus subtilis
No full textMicro-nutrient deficiency has been a contributing factor to several metabolic and health-related defects. Incorporation of these micronutrients in food products is the sole remedy for this deficiency, and this could be satisfied by the process of biofortification. In India, crabs are cultured within an integrated farming system. Malnutrition, particularly micronutrient deficiencies, remains a leading factor behind non-communicable diseases. In this study, we used riboflavin (vitamin B2) produced by Bacillus subtilis to enhance the nutritional value of crabs. The crabs that received riboflavin showed signs of reduced stress, better immunity, and higher levels of protein, carbohydrates, and fats. There was also a noticeable drop in harmful bacterial count, and histology studies showed increased muscle fibers among the riboflavin-treated groups. These findings highlight the potential of utilizing natural, microbe-based methods to enhance the nutritional value of everyday food and promote better public health. The solution for the micronutrient deficiency is the usage of the biofortified food. 
QUANTITATIVE CHANGES IN ORGANIC CONTENTS DUE TO CERTAIN NERUROTRANSMITTERS IN A MALE FRESHWATER CRAB, PARATELPHUSA HYDRODROMOUS
No full textThe organic compounds like protein, carbohydrate and lipids have been quantitatively estimated after injecting fenfluramine. Octopamine and dopamine to a male freshwater crab, Paratelphusa hydrodromous. Tissue such as haemolymph. hepatopancreas and testis were tested for organic contents and all the tissues showed fluctuations in their contents due to Octopamine, dopamine and fenfluramine treatments
Filtering Techniques for Improving Radio-Frequency Identification Machine Control
No full textabstract: Human operators have difficulty driving cranes quickly, accurately, and safely because of the slow response of heavy crane structures, non-intuitive control interfaces, and payload oscillations. Recently, a novel hand-motion crane control system has been proposed to improve performance by coupling an intuitive control interface with an element that reduces the complex oscillatory behavior of the payload. Hand-motion control allows operators to drive a crane by simply moving a hand-held radio-frequency tag through the desired path. Real-time location sensors are used to track the movements of the tag and the tag position is used in a feedback control loop to drive the crane. An input shaper is added to eliminate dangerous payload oscillations. However, tag position measurements are corrupted by noise. It is important to understand the noise properties so that appropriate filters can be designed to mitigate the effects of noise and improve tracking accuracy. This work discusses implementing filtering techniques to address the issue of noise in the operating environment. Five different filters are used on experimentally-acquired tag trajectories to reduce noise. The filtered trajectories are then used to drive crane simulations. Filter performance is evaluated with respect to the energy usage of the crane trolley, the settling time of the crane payload oscillations, and the safety corridor of the crane trajectory. The effects of filter window lengths on these parameters are also investigated. An adaptive filtering technique, namely the Kalman filter, adapts to the noise characteristics of the workspace to minimize the tag tracking error and performs better than the other filtering techniques examined.Dissertation/ThesisM.S. Bioengineering 201
