La voie de régulation de la traduction de l’ARNm ASH1 : une concertation entre Khd1, Puf6 et Loc1

La localisation des ARNm par transport dirigé joue un rôle dans le développement, la motilité cellulaire, la plasticité synaptique et la division cellulaire asymétrique. Chez la levure Saccharomyces cerevisiæ, la localisation d’ARNm est un phénomène dont les mécanismes de régulation sont conservés auprès de nombreux autres organismes. Lors de la division de la levure, plus d’une trentaine de transcrits sont localisés par transport actif à l’extrémité du bourgeon de la cellule-fille. Parmi ceux-ci, l’ARNm ASH1 est le mieux caractérisé et constitue le modèle utilisé dans cette étude. Pour exercer sa fonction, la protéine Ash1 doit être produite uniquement après la localisation de l’ARNm ASH1. Pour ce faire, les mécanismes de régulation de la traduction de l’ARNm ASH1 empêchent son expression durant le transport. Ce projet de recherche vise à étudier les mécanismes de régulation de la traduction de l’ARNm ASH1 par les répresseurs traductionnels connus, soit Khd1, Puf6 et Loc1. Les études antérieures se sont penchées sur ces facteurs de manière individuelle. Cependant, dans cette étude, nous avons exploré la présence d’une collaboration entre ceux-ci. Ainsi, nous avons voulu déterminer si les répresseurs traductionnels peuvent être intégrés en une seule voie de régulation de la traduction de l’ARNm ASH1. De plus, nous avons cherché à identifier le mécanisme de recrutement des répresseurs traductionnels sur l’ARNm ASH1, qui correspond au point initial des voies de régulations de l’ARNm ASH1. Nos résultats montrent que les répresseurs traductionnels de l’ARNm ASH1, soit Khd1 et Puf6, font partie d’une même voie de régulation de la traduction. Le rôle du facteur nucléaire Loc1 dans la voie de régulation de la traduction, quant à elle, a été examinée à partir d’expériences permettant l’étude du mécanisme de recrutement des répresseurs traductionnels dans le noyau. Ainsi, nos travaux montrent que Puf6 et Loc1 sont associés de manière ARN-dépendant avec la machinerie de transcription, notamment au facteur d’élongation de la transcription Spt4-Spt5/DSIF. Par ailleurs, notre laboratoire a précédemment montré que la localisation nucléaire de la protéine de liaison à l’ARN She2 est essentielle au recrutement des facteurs Loc1 et Puf6 sur l’ARNm ASH1. Des expériences d’immunoprécipitation de la chromatine (ChIP) supportent l’hypothèse que le recrutement de Loc1 est essentiel à celui de Puf6, qui s’effectue ultérieurement. Ainsi, à partir des résultats de cette étude et des résultats publiés précédemment dans notre laboratoire, nous avons élaboré un modèle de recrutement coordonné des facteurs She2, Loc1 et Puf6 sur l’ARNm ASH1 naissant. De manière générale, cette étude a permis d’établir la présence d’une seule voie de régulation de la traduction de l’ARNm ASH1 et une meilleure connaissance du recrutement des facteurs de répression traductionnelle sur celui-ci.

Studies on the Dipping Characteristics of RVNRL and NRLatex Compounds

ABSTRACT: The dipping characteristics of radiation-vulcanized natural rubber latex and natural rubber latex compounds were investigated with a lab-model semiautomatic dipping machine. The effect of the variation of the speed of immersion and withdrawal, dwell time, compound viscosity, and concentration of coagulant on the thickness of the latex deposit was investigated. The results of the study show that the deposit thickness depends on the withdrawal speed of the former, the concentration of the coagulant, dwell times, and the viscosity of the latex compounds

Studies on Lactic Acid Bacteria from Tropical Fish and Shellfish

In this study, an attempt has been made to gather enough information regarding lactic acid bacteria from fish and shellfish of tropical regions. The occurrence and distribution of lactic acid bacteria in fresh and frozen marine fish and shellfish, farmed fish and shellfish, cured and pickled fish and shellfish have been investigated. Lactic Acid Bacteria (LAB) have for centuries been responsible for the fermentative preservation of many foods. They are used to retard spoilage and preserve foods through natural fermentations. They have found commercial applications as starter cultures in the dairy, baking, meat, fish, and vegetable and alcoholic beverage industries. They are industrially important organisms recognized for their fermentative ability as well as their nutritional benefits. These organisms produce various compounds such as organic acids, diacetyl, hydrogen peroxide and bacteriocins or bactericidal proteins during lactic fermentations.Biopreservation of foods using bacteriocin producing LAB cultures is becoming widely used. The antimicrobial effect of bacteriocins and other compounds produced during fermentation of carbohydrates are well known to inhibit the growth of certain food spoiling bacteria as well as a limited group of food poisoning and pathogenic bacteria LAB like Lactobacillus plantarum are widely used as starter cultures for the Production of fish ensilage. The present study is the first quantitative and qualitative study on the occurrence and distribution of lactic acid bacteria in fresh and frozen fish and prawn. It is concluded that Lactobacillus plantaruni was the predominant lactobacillus species in fresh and frozen fish and shellfish. The ability of selected Lactobacillus cultures to grow at low temperatures, high salt content, produce bacteriocins, rapidly ferment sugars and decrease the pH make them potential candidates for biopreservation of fish and shellfish.

Effect of mechanical milling on the structural, magnetic and dielectric properties of coprecipitated ultrafine zinc ferrite

Nanosized ZnFe2O4 particles containing traces of a-Fe2O3 by intent were produced by low temperature chemical coprecipitation methods. These particles were subjected to high-energy ball milling. These were then characterised using X-ray diffraction, magnetisation and dielectric studies. The effect of milling on zinc ferrite particles have been studied with a view to ascertaining the anomalous behaviour of these materials in the nanoregime. X-ray diffraction and magnetisation studies carried out show that these particles are associated with strains and it is the surface effects that contribute to the magnetisation. Hematite percentage, probably due to decomposition of zinc ferrite, increases with milling. Dielectric behaviour of these particles is due to interfacial polarisation as proposed by Koops. Also the defects caused by the milling produce traps in the surface layer contributes to dielectric permittivity via spin polarised electron tunnelling between grains. The ionic mechanism is enhanced in dielectrics with the rise in temperature which results in the increase of dielectric permittivity with temperature.

Studies on exopolysaccharide production by probiotic Lactic acid bacteria

The thesis mainly discussed the isolation and identification of a probiotic Lactobacillus plantarum, fermentative production of exopolysaccharide by the strain, its purification, structural characterisation and possible applications in food industry and therapeutics. The studies on the probiotic characterization explored the tolerance of the isolated LAB cultures to acid, bile, phenol, salt and mucin binding. These are some of the key factors that could satisfy the criteria for probiotic strains . The important factors required for a high EPS production in submerged fermentation was investigated with a collection of statistical and mathematical approach. Chapter 5 of the thesis explains the structural elucidation of EPS employing spectroscopic and chromatographic techniques. The studies helped in the exploration of the hetero-polysaccharide sequence from L. plantarum MTCC 9510. The thesis also explored the bioactivities of EPS from L. plantarum. As majority of chemical compounds identified as anti-cancerous are toxic to normal cells, the discovery and identification of new safe drugs has become an important goal of research in the biomedical sciences. The thesis has explored the anti-oxidant, anti-tumour and immunomodulating properties of EPS purified from Lactobacillus plantarum. The presence of (1, 3) linkages and its molecular weight presented the EPS with anti-oxidant, anti-tumour and immunomodulating properties under in vitro conditions.

Influence of dopants on the properties of maghemite

Preparatiun or aci cular maghemi te containing dopan ls li ke Mg. i and Gd and their characleris,llion us ing different analytica l techniques have been reported. These in vestigat ions reveal that the addition of dopants li ke Mg. Ni and Gd modifies the magnetic properties without cfrecting any structural changes. The opt ical bandgaps of these doped compositions have ,li S() hecn determ ined. Evidence is ,li so av,li lab le from spectroscopic investi gations suggest ing thalmaghcllli te prepared vi,l the ()xa l,ltc precursor route does nm exhi bit a hydrogen fe rrite structure

NI USRP Lab: DQPSK Receiver Design

Design a DQPSK receiver using LabVIEW for implementation on NI USRP.

WAIS seminar: Research Discussion: Lab of Things? What Things?

Wednesday 19th March 2014 Speaker(s): Kirk Martinez, Dr Jonathon S Hare and Dr Enrico Costanza Organiser: Dr Tim Chown Time: 19/03/2014 11:00-11:50 Location: B32/3077 File size: 676 Mb Abstract The new WAIS seminar series features classic seminars, research discussions, tutorial-style presentations, and research debates. This seminar takes the form of a research discussion which will focus on the Internet of Things (IoT) research being undertaken in WAIS and other research groups in ECS. IoT is a significant emerging research area, with funding for research available from many channels including new H2020 programmes and the TSB. We have seen examples of IoT devices being built in WAIS and other ECS groups, e.g. in sensor networking, energy monitoring via Zigbee devices, and of course Erica the Rhino (a Big Thing!). The goal of the session is to briefly present such examples of existing Things in our lab with the intent of seeding discussion on open research questions, and therefore future work we could do towards new Things being deployed for experimentation in Building 32 or its environs. The session will discuss what 'things' we have, how they work, what new 'things' might we want to create and deploy, what components we might need to enable this, and how we might interact with these objects.

On lions, impala, and bigraphs: modelling interactions in Ubiquitous Computing

As ubiquitous systems have moved out of the lab and into the world the need to think more systematically about how there are realised has grown. This talk will present intradisciplinary work I have been engaged in with other computing colleagues on how we might develop more formal models and understanding of ubiquitous computing systems. The formal modelling of computing systems has proved valuable in areas as diverse as reliability, security and robustness. However, the emergence of ubiquitous computing raises new challenges for formal modelling due to their contextual nature and dependence on unreliable sensing systems. In this work we undertook an exploration of modelling an example ubiquitous system called the Savannah game using the approach of bigraphical rewriting systems. This required an unusual intra-disciplinary dialogue between formal computing and human- computer interaction researchers to model systematically four perspectives on Savannah: computational, physical, human and technical. Each perspective in turn drew upon a range of different modelling traditions. For example, the human perspective built upon previous work on proxemics, which uses physical distance as a means to understand interaction. In this talk I hope to show how our model explains observed inconsistencies in Savannah and ex- tend it to resolve these. I will then reflect on the need for intradisciplinary work of this form and the importance of the bigraph diagrammatic form to support this form of engagement. Speaker Biography Tom Rodden Tom Rodden (rodden.info) is a Professor of Interactive Computing at the University of Nottingham. His research brings together a range of human and technical disciplines, technologies and techniques to tackle the human, social, ethical and technical challenges involved in ubiquitous computing and the increasing used of personal data. He leads the Mixed Reality Laboratory (www.mrl.nott.ac.uk) an interdisciplinary research facility that is home of a team of over 40 researchers. He founded and currently co-directs the Horizon Digital Economy Research Institute (www.horizon.ac.uk), a university wide interdisciplinary research centre focusing on ethical use of our growing digital footprint. He has previously directed the EPSRC Equator IRC (www.equator.ac.uk) a national interdisciplinary research collaboration exploring the place of digital interaction in our everyday world. He is a fellow of the British Computer Society and the ACM and was elected to the ACM SIGCHI Academy in 2009 (http://www.sigchi.org/about/awards/).

Advances in animal blood processing: development of a biopreservation system and insights on the functional properties of plasma

La sang és un subproducte amb un alt potencial de valorització que s'obté en quantitats importants en els escorxadors industrials. Actualment, la majoria de sistemes de recollida de la sang no segueixen unes mesures d'higiene estrictes, pel que esdevé un producte de baixa qualitat microbiològica. Conseqüentment, l'aprofitament de la sang és una sortida poc estimulant des del punt de vista econòmic, ja que acostuma a perdre les qualitats que permetrien l'obtenció de productes d'alt valor afegit. El capítol I del present treball s'inclou dins d'un projecte que proposa la inoculació de bacteris de l'àcid làctic (LAB) com un cultiu bioconservador de la sang, un sistema senzill i de baix cost que cerca l'estabilitat de la sang, tant microbiològica com fisicoquímica, durant el període del seu emmagatzematge. El capítol II s'emmarca dins d'un projecte que cerca la millora de l'aprofitament integral de la sang que, en el cas de la fracció plasmàtica, es centra en l'estudi de la funcionalitat dels seus principals constituents. Conèixer la contribució dels components majoritaris ha de permetre la millora de la funcionalitat dels ingredients alimentaris derivats. Els resultats presentats en aquesta tesi poden ajudar a la valorització de la sang porcina d'escorxadors industrials, mitjançant els coneixements adquirits pel que fa a la millora del seu sistema de recollida i del desenvolupament d'ingredients alimentaris amb interessants propietats funcionals.

Changes in heron and egret populations on the Laurentian Great Lakes and connecting channels, 1977-2009

Canadian and U.S. federal wildlife agencies completed four decadal surveys, spanning the years 1977 to 2009, to census colonial waterbirds breeding on the Great Lakes and adjoining bodies of water. In this paper, we reports abundance, distribution, and general population trends of three species: Black-crowned Night-Heron (Nycticorax nycticorax), Great Egret (Ardea alba), and Great Blue Heron (Ardea herodias). Estimates of nest numbers ranged from approximately 4000-6100 for the Black-crowned Night-Heron, 250-1900 for the Great Egret, and 3800-6400 for the Great Blue Heron. Average annual rates of change in nest numbers between the first (1977) and fourth (2008) census were −1% for the Black-crowned Night-Heron, +23% for the Great Egret, and −0.27% for the Great Blue Heron. Across the 30-year census, Black-crowned Night-Heron estimates decreased in U.S. (−57%) but increased (+18%) in Canadian waters, Great Egret nests increased 1381% in Canadian waters with a smaller, but still substantial increase in the number of nests at U.S. colonies (+613%), and Great Blue Heron numbers increased 148% in Canadian waters and 713% in U.S. waters. Although a single factor cannot be clearly linked to changes observed in each species’ distribution, hydrological variation, habitat succession, nest competition with Double-crested Cormorants (Phalacrocorax auritus), and land use changes likely all contributed. Management activities should support both breeding and foraging conditions including restoration of early successional habitats and anticipate continued northward expansions in the distributions of these waterbirds.

Effect of temperature and salt on the maturation of white-salted cheese

White-salted cheeses were prepared from ultrafiltered (UF) cows' milk and salted to give final salt-in-moisture (SM) levels of 2.5, 3.2 and 4.0%. The cheeses were stored at 5degreesC and 10degreesC for up to 15 weeks. The microflora was dominated by lactic acid bacteria (LAB) but some mould growth was evident within 15 weeks at all SM levels and both temperatures. Levels of water-soluble nitrogen (WSN), attributed to chymosin activity, increased significantly with time, the rate being inversely proportional to the SM level and increasing with storage temperature. Similar effects were noted for trichloroacetic acid-soluble nitrogen (TCA-SN) and free amino acid (FAA) levels, both of which would also be affected by bacterial protease activity. The proteolytic activity was reflected by changes in the hardness and fracturability of the cheeses.

Soft-bit and numerical precision requirements on multiband full-rate ultra-wideband (UWB) receivers

This paper discusses the architectural design, implementation and associated simulated peformance results of a possible receiver solution fir a multiband Ultra-Wideband (UWB) receiver. The paper concentrates on the tradeoff between the soft-bit width and numerical precision requirements for the receiver versus performance. The required numerical precision results obtained in this paper can be used by baseband designers of cost effective UWB systems using Systein-on-Chip (SoC), FPGA and ASIC technology solutions biased toward the competitive consumer electronics market(1).

Numerical precision requirements on the Multiband Ultra-Wideband system for practical consumer electronic devices

This paper discusses the requirements on the numerical precision for a practical Multiband Ultra-Wideband (UWB) consumer electronic solution. To this end we first present the possibilities that UWB has to offer to the consumer electronics market and the possible range of devices. We then show the performance of a model of the UWB baseband system implemented using floating point precision. Then, by simulation we find the minimal numerical precision required to maintain floating-point performance for each of the specific data types and signals present in the UWB baseband. Finally, we present a full description of the numerical requirements for both the transmit and receive components of the UWB baseband. The numerical precision results obtained in this paper can then be used by baseband designers to implement cost effective UWB systems using System-on-Chip (SoC), FPGA and ASIC technology solutions biased toward the competitive consumer electronics market(1).

Cyborg 1.0

I was born human. But this was an accident of fate - a condition merely of time and place. I believe it's something we have the power to change. I will tell you why. In August 1998, a silicon chip was implanted in my arm, allowing a computer to monitor me as I moved through the halls and offices of the Department of Cybernetics at the University of Reading, just west of London, where I've been a professor since 1988. My implant communicated via radio waves with a network of antennas throughout the department that in turn transmitted the signals to a computer programmed to respond to my actions. At the main entrance, a voice box operated by the computer said "Hello" when I entered; the computer detected my progress through the building, opening the door to my lab for me as I approached it and switching on the lights. For the nine days the implant was in place, I performed seemingly magical acts simply by walking in a particular direction. The aim of this experiment was to determine whether information could be transmitted to and from an implant. Not only did we succeed, but the trial demonstrated how the principles behind cybernetics could perform in real-life applications.