This Bachelor thesis is a part of a bachelor project which includes building, programming and controlling a 3DOF tandem helicopter. This particular report deals with the propulsion units, i.e. the motors and propellers of the helicopter. It covers the process of how to determine the most suitable propulsion units for the rig that eventually will enable it to run. To achieve this, different data have been processed. Torque and thrust are two important parameters that have been studied. The data have been acquired by different tests, e.g. thrust measurements from a thrust rig. Also more complex analysis such as Blade Element Theory and Actuator Disk Theory have been carried out in order to determine the behaviour of the propulsion units. Study data sheets and databases was also a part of the work. The result of this work was two equal propulsion units which were mounted in the helicopter. They proved to work satisfactory and provided wanted dynamics to the system. / Design & Implementation of a 3DOF Helicopter

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this work is to study and characterize aerodynamically a free jet operating at subsonic regime and identify its acoustic signature. This study aims to analyze fundamentally the turbulent structures and the total noise produced at different Mach numbers. This kind of research is crucial to the understanding of these mechanisms of noise generation and propagation, and it is extremely important for aeronautical applications, for instance, the jet engine exhaust. The research is done by analysing the data obtained in experiments using pitot tube, hot-wire anemometer and acoustic measurements. This work also describes the experimental procedures for each step of analysis, as well as the characteristics of jet noise facilities. The data from measurements with a pitot tube was used to study the mean velocity profiles. The average properties are also analyzed with an anemometry system, likewise used to study the turbulent intensity at eleven axial lines, ranging from the centerline to the edge of the nozzle (lipline). These results are compared with literature and has verified the accuracy of hot-wire anemometers for turbulent intensities lower than 15%. The aerodynamic data are obtained for Mach numbers 0.25, 0.50 and 0.75, from the nozzle exit to thirteen diameters in the direction of the jet. The acoustic study is carried out by analyzing the sound pressure level obtained at six positions in the far field, with observer angles ranging from 40 to 110º. In this campaign more velocities are studied with Mach numbers from 0.18 to 1.00 with step of 0.05 are described. A database with the sound pressure level as a function of frequency is constructed from this information. / O objetivo deste trabalho é estudar e caracterizar aerodinamicamente um jato livre operando em regime subsônico e identificar a assinatura acústica do mesmo. Esse estudo busca analisar fundamentalmente as estruturas turbulentas e o ruído total produzido em diferentes números de Mach. Tal estudo é crucial para o entendimento desses mecanismos de geração e propagação, e encontra extrema importância para aplicações aeronáuticas, como, por exemplo, a exaustão de motores a reação (jato). A investigação é feita através da análise dos dados obtidos em experimentos utilizando tubo de pitot, anemômetro de fio-quente e ensaios acústicos. Neste trabalho também são descritos os procedimentos experimentais de cada etapa de análise, bem como as características dos laboratórios utilizados para o estudo do ruído de jato. Com os dados provenientes das medições com tubo de pitot são estudados os perfis de velocidade média. As propriedades médias também são analisadas com o sistema de anemometria, que ainda é utilizado para estudo da intensidade turbulenta em onze linhas axiais, variando da linha de centro até a borda do bocal (lipline). Estes resultados são comparados com a literatura e é constatada a acurácia dos anemômetros de fio-quente para intensidades turbulentas menores que 15%. Os dados aerodinâmicos mencionados são obtidos para números de Mach 0,25, 0,50 e 0,75, a partir da saída do bocal até treze diâmetros na direção do jato. O estudo acústico é feito através da análise do nível de pressão sonora obtido em seis posições no campo distante, com ângulos de observação variando de 40 a 110º. Diferentes velocidades também foram analisadas, desta vez, com números de Mach de 0.18 a 1.00 com passo de 0.05. Um banco de dados com o nível de pressão sonora em função da frequência é construído a partir destas informações. / Mestre em Engenharia Mecânica

Lors d'une infection virale, l'hôte déclenche une réponse rapide, la rémonse immunitaire innée, dont l'interféron (IFN) de type I est la cytokine centrale. Des motifs moléculaires associés aux micro-organismes (MAMP) sont déteectés par de nombreux récepteurs dédiés, dont les récepteurs cytoplasmiques de type RIG-I (RLR) identifiés à partir de 2004. Les RLR, au nombre de trois, RIG-I, MAD5 et LGP2, sont les ARN-hélicases composées de deux ou trois types de domaines : deux domaines CARD, resposables du recrutement de la cascade de signalisation, un domaine C-terminal CTD, site de liaison initial de l'ARN viral, et le domaine central hélicase, site secondaire de liaison àl'ARN et possédant également une activité enzymatiques ATP-dépendante. RIG-I est impliqué dans la détection de plusieurs virus dont ceux de l'ordre des mononegavirales (virus de la rage, de la rougeole, Ebola). Ce récepteur reconnait des ARN viraux possédant une région double brin adjacente à une extrémité 5'-triphosphate. Les nombreuses études menées n'ont cepnedant pas encore permis de dégager un mécanisme complet et cohérent de l'activation de RIG-I. Notre objectif était donc d'apporter des réponses molécualires quant au mécanismes d'activation de RIG-I. Dans un premier temps, l'élucidation de la structure de la protéine entière RIG-I de canard, par l'équipe de Stephen Cusack, leur a permis d'identifier une conformation auto-réprimée de la protéine. En l'absence d'ARN le domaine CARD2 interagit avec le sous domaine Hel2i du domaine hélicase. Nous avons apporté une preuve fonctionelle de cette observation. Les mutations F540 A/D, du résidu situé dans le sous domaine Hel2i, inhibent l'interaction CARD2-Hel2i et produisent des mutant constituvement actifs. A l'opposé, les mutations correspondantes dans le domaine CARD2 rendent RIG-I inactif. L'interaction CARD2-Hel2i semble donc impliquer une double auto-répression via (i) le masquage du site de liaison à l'ARN du sous-domaine Hel2i, et (ii) le masquage de résidus du domaine CARD2 impliqués dans le recrutement d'intermédiaires requis pour la transduction du signal. Par ailleurs, l'étude de mutants impliqués dans la liaison et l'hydrolyse de l'ATP nous a permis de proposer un nouveau rôle régulateur pour cette activité enzymatique. Dans un deuxième temsp, l'étude de la nécessité de l'oligomérisation de RIG-I pour l'activation de la réponse IFN a été menée. Eva Kowalinski, en thèse dans l'équipe de Stephen Cusack, n'observe la formation de dimères de RIG-I, in vitro, qu'en présence d'un ARN synthétique possédant deux extrémités 5'-triphosphate. Nous avons complété cette observation avec des analyse montrant que des ARN synthéttiques leader incapables d'induire la dimérisation de RIG-I in viro, activent néanmoins ce récepteur in cellula. Par ailleurs, nim'utilisation de la technique de co-immunoprécipitation, ni celle du test de complémentation basé sur la luciférase Gaussia, avec ou sans activiation par un ARN ou une infection virale, n'ont permis d'observer d'oligomérisation de RIG-I. L'auto-association de RIG-I ne semble donc pas être indispensable pour son activation. / Vertebrate are permanently threatened by infections that they manage to counteract using a dedicated system. The innate immunity allows a rapid response against viral infection, mainly through the type I interferon (IFN) production. Dedicated receptors detect microbe-associated molecular patterns (MAMPs), and among them the RIG-likereceptors (RLRs), RIG-I, MDA5 and LGP2, can sense viral RNA into the cytoplasm. RLRs are compossed of two or three different domains : two N-terminal CARDs domains are resposible for signal transduction, a C-terminal domains is the first RNA binding site, and a central helicase domainis the second RNA binding site and possesses an ATP-dependent activity. RIG-I is important for sensing of several mononegavirales, such as rabies, measle and Ebola viruses, and recongnized 5'-triphosphorylated double stranded RNA. Despite intensive studies, a full and comprehensive model of the mechanismof RIG-I activation is still lacking. Our aim was to clarify the first molecular steps of RIG-I activation. First, Stephen Cusack's team elucidated the structure of the full lenght duck RIG-I protein and identified the principle of RIG-I auto-repressed conformation. In absence of ligand RNA, CARD2 domain interacts with Hel2i subdomain of helicase domain. We confirmed this conformation with functional evidence. Mutaions F540A/D, in Hel2i subdomain, inhibits CARD2:Hel2i interaction and renders RIG-I constitutively active. In contrast, the corresponding mutations in the Hel2i contacting site of CARD2 domain produce inactive mutants. Thus CARDS;Hel2i interactio induces an auto-repressed state through a deual masking of both Hel2i RNA binding site and CARD2 residus necessary for signal transduction. Moreover, study of mutants involved in ATP binding and hydrolysis reealed a portential unsuspected regulatory role for the ATP-dependent enzymatic activity of RIG-I. Second, we studied the necessity of RIG-I oligomerization for RIG-I activation. Eva Kowalinski, PhD student in Stephen Cusack's team, observed RIG-I dimers in vitro, only in presence of synthetic RNA with two 5'triphosphorylated ends. We complete this observation with functional assays showing that synthetic leader RNA incapable to induce RIG-I oligomerization in vitro, did activate RIG-I in cellula. Moreover, we did not observe RIG-I oligomerization using either co-immunoprecipitation or Gaussia Luciferase-based-protein complementation assay, after activation with cognate RNA or viral infection. Altogether our results indicate that the self-oligomerization og RIG-I is either dispensable or very transient for signal transduction.

Erasteel Kloster i Långshyttan är en stålindustri som bland annat valsar tråd och tunna band.Kvalitén på det valsade stålet undersöks med en elektromagnetisk sensor. Denna sensorkalibreras med hjälp av en testrigg där sensorerna testas med olika provpinnar med defekter.Provpinnarna förs fram och tillbaka genom sensorn som undersöks, vilken ger utslag på dentillkopplade datorn. Dessa utslag används sedan för att kalibrera inställningarna hossensorerna samt för att testa om de fungerar. Syftet med följande studie är att undersöka förbättringsmöjligheterna hos denna testrigg samtta fram ett lösningsförslag på en förbättrad konstruktion. Den nuvarande testriggens problemidentifieras genom en intervju och observationer. Olika konceptidéer togs fram, undersöktesoch diskuterades med företagets krav samt de nuvarande problemen som grund. Olikakomponenter, exempelvis drivenhet och glidskenor som passar ändamålet identifieras. Medhjälp av dessa framställs sedan flera förbättringskoncept, vars egenskaper jämförs gentemot Erasteels önskemål. Resultatet av studien blev en modell av en ny testrigg, ritad i Solidworks. Denna modell bestårav en sammanställning av de delkoncept som uppfyllt flest krav på bästa sätt, vilket harbestämts med hjälp av en Pughs konceptvalsmatris. Denna nya modell löser de problem somidentifierats hos den gamla testriggen samtidigt som den blir mer användarvänligt. Dettagjordes genom att drivenheten konstruerades om samt att den gamla motorn ersattes med enlinjärmotor. Även sensorns hållare modifierades för att kunna förflyttas medan sensorn är påplats, vilket förenklar bytet av provpinnen. Det nya testriggsförslaget kommer sedan utgöraunderlaget vid konstruktionen av en ny testrigg hos Erasteel. / Erasteel Kloster in Långshyttan is a steelwork that among other things hot rolls iron. The quality of the rolled iron is inspected by an electromagnetic sensor. This sensor is calibrated using a test rig and a test material with a defect. This test material is moved back and forth through the sensor, which gives different outputs depending on the fault. These outputs are then used to calibrate the sensor settings. This study aims to examine possible improvements of the currently used test rig as well as to develop a proposal for an improved rig. The current problems are identified from interviews and observations. Different concept ideas were developed, examined, and discussed with the companies wishes and the identified problems as a foundation. Different fitting components such as drive units and linear rails which can be purchased have been identified. Various improvement concepts were created based on the old test rig, while the identified problems and the wishes of Erasteel were taken into consideration. This work resulted in a new model of a test rig, made with Solidworks. The design is created with the concepts that satisfy the companies demands in the best way, which was evaluated with the Pugh concept matrix. The final proposal solves all identified problems which are associated with the old rig, while at the same time being more user friendly. This new rig will be the basis for the new machine which will be built at Erasteel.

Sverige finns det Riksidrottsgymnasier och Nationella idrottsutbildningar som erbjuder ett utbildningsprogram med specialidrott för att elitidrottande ungdomar ska kunna kombinera idrott och studier. Ungdomarna ska få möjlighet att utvecklas både inom sin idrott och inom sin utbildning och på så sätt bli ”vinnare i långa loppet” med både en idrottskarriär och sedan även en yrkeskarriär som de lagt grunden till med studier under idrottsåren. För att ungdomar ska lyckas med elitidrott och studier är det viktigt att se till helheten. Tidigare forskning inom ”dubbla karriärer” tar utgångspunkt från det holistiska perspektivet som beskriver betydelsen av balans mellan idrott, skola och privatliv. Studierna nämner helheten som viktig för ungdomar ska må bra och kunna prestera i sin idrott och i sin utbildning. De olika forskningsstudierna utgår och lägger tyngdpunkten på idrottsdelen, idrottsmiljöerna och tränare. De pekar på betydelsen av skolan och på betydelsen av helheten idrott, skola och privatliv men går ej på djupet med hur lärarens undervisning eller elevens lärande ska utformas för bästa resultat. Diskursen som analyseras i detta arbete är ”matematikundervisning på ett idrottsgymnasium”. Forskningsfrågan som ställs och som formar diskursen lyder: Vilka är de didaktiska perspektiven i idrottselevernas utbildningsmiljö, specifikt inom matematikundervisning och vad görs viktigt i matematikundervisningen sedd som diskurs? Matematiklärarna och idrottseleverna sätts i fokus och studien undersöker, hur de beskriver olika företeelser när de ger sin bild av matematikundervisningen på skolan. Studien tar utgångspunkt från det didaktiska perspektivet/lärarperspektivet i idrottselevernas utbildningsmiljö. Data samlades in genom intervjuer med matematiklärare och en enkät till idrottselever på ett Riksidrottsgymnasium med cirka 60 idrottselever, under vårterminen 2019. I analysresultatet framstår diskursens normer, högt värderade ståndpunkter och dilemma som fem teman: ”det viktiga matematikämnet”, ”den goda idrottseleven”, ”dilemmat runt idrottselevens frånvaro”, ”strategier för stöd” och ”studieformens otydlighet”. Slutsatsen pekar på att det så tydligt frammanas en ideal bild av en framgångsrik elev, att matematikämnet värderas så viktigt och svårt utifrån sin tradition och att den specifikastudieformen för matematikundervisning för idrottselever saknar tydlig form. Studieformen kan beskrivas som lärarledd klassrumsundervisning kompletterad med olika anpassningar för att underlätta för idrottselevernas självstudier. Studiens diskursiva analys beskriver också vad som ses som framgångsfaktorer, vilket sammanfattas i idrottselevernas stora egna ansvar, motivation och förmåga att planera in och genomföra självstudier samt matematiklärarnas olika anpassningar och stöd för att underlätta idrottselevernas självstudier. / The Swedish model of elite sports secondary schools consist of Riksidrottsgymnasium, RIG,and National Sports Education Programs, NIU, which offer a training program with specialized sports to student-athletes in order for them to combine sport and study. The underlying philosophy for the model is seen as creating “winners in the long run” in preparingstudent-athletes for a post-athletic career, as well as coping with current demands to optimise development in an elite sporting career. For young student-athletes to successfully combine elite sport and study, it is important tohave a holistic perspective. Previous research in “dual careers” is based on the holistic perspective that describes the importance of a balance between sport, school and private life. The studies point out that the student-athlete has a challenging life situation to manage andit is important for the young student-athlete to feel good to be able to perform both in sportand study. The various research studies are based on and emphasize the sport, the sportenvironments and coaches. They put focus on the importance of the education and theimportance of the holistic perspective of sport, school and private life but do not go into depthhow the teacher's teaching or the student's way of learning should be designed for best results. This discourse analysis is defined as “mathematics at an elite sport secondary school”. The research question which shapes the given discourse reads: “What are the didactic perspectives in the student-athlete's educational environment, especially in mathematics teaching, seen as discourse?” The math teachers and the student-athletes are put into focus and the study investigates how they describe the math education at the RIG-school. The study is based onthe didactic perspective/teaching perspective in the student-athlete's educational environment. Data for the study was collected through interviews with math teachers and a questionnairefor student-athletes, at a RIG-school with approximately 60 student-athletes, during thespring of 2019.In the results of the analysis, the norms of the discourse, highly valued positions and dilemmaappear as five themes: “the important math-subject”, “the good student-athlete”, “thedilemma of the student-athlete's absence”, “strategies for support” and “the ambiguity of theform of the mathematics education”. These findings point to the fact that an ideal image of a successful student-athlete is clearly presented, that the math-subject is valued important and difficult based on its tradition and that the specific study form for mathematics education for student-athletes lacks a clear form. The model that is applied for the mathematics education at the RIG-school can be describedas teacher-led classroom education supplemented with various adaptations to facilitate the student-athletes' self-studies. In this study the discursive analysis also point out the success factors, which are summarized as the student-athletes' high responsibility, motivation and ability to plan and carry out self studies as well as the math teachers' various adaptations and support to facilitate the student athletes' self-studies.

BACKGROUND: The type I interferon (IFN) response is a critical component of the innate immune response to infection by RNA viruses and is initiated via recognition of viral nucleic acids by RIG-like receptors (RLR). Engagement of these receptors in the cytoplasm initiates a signal transduction pathway leading to activation of the transcription factors NF-κB, ATF-2 and IRF-3 that coordinately upregulate transcription of type I IFN genes, such as that encoding IFN-β. In this study the impact of poliovirus infection on the type I interferon response has been examined. METHODS: The type I IFN response was assessed by measuring IFN-β mRNA levels using qRT-PCR and normalizing to levels of β-actin mRNA. The status of host factors involved in activation of the type I IFN response was examined by immunoblot, immunofluorescence microcopy and qRT-PCR. RESULTS: The results show that poliovirus infection results in induction of very low levels of IFN-β mRNA despite clear activation of NF-κB and ATF-2. In contrast, analysis of IRF-3 revealed no transcriptional induction of an IRF-3-responsive promoter or homodimerization of IRF-3 indicating it is not activated in poliovirus-infected cells. Exposure of poliovirus-infected cells to poly(I:C) results in lower levels of IFN-β mRNA synthesis and IRF-3 activation compared to mock-infected cells. Analysis of MDA-5 and IPS-1 revealed that these components of the RLR pathway were largely intact at times when the type I IFN response was suppressed. CONCLUSIONS: Collectively, these results demonstrate that poliovirus infection actively suppresses the host type I interferon response by blocking activation of IRF-3 and suggests that this is not mediated by cleavage of MDA-5 or IPS-1.

Det här examensarbetet skildrar en konceptstudie och kostnadsuppskattning av enuniversell testrigg för växellådor. Arbetet har genomförts på uppdrag av SwepartTransmission AB och har resulterat i koncept- och komponentförslag samtkostnadsuppskattning av ett universellt test system av växellådor. / This degree project cover a concept study and cost analyses of a universal test rig forgears. The project has been performed for Swepart Transmission AB and has resultedin a concept and component suggestion as well as cost analysis of a universal testsystem for gears.

Powder metallurgy (PM) is usually used in manufacturing parts with complex geometries, such as gears and structural parts. The main attractions of PM are the high rate of material utilization, environmental friendliness of production, economic advantages (especially for complex geometries), and possibility of obtaining lighter components. To find a wide range of applications and compete with regular steel gears, PM gear transmissions should have good transmission efficiency and wear properties. Furthermore, they should have low contact noise and adequate surface fatigue properties. Because of the porosity structure of PM gears both on gear flanks and in the body, the friction and wear properties of PM gear flank contacts differ somewhat from those of regular steel gears.    This doctoral thesis examines the efficiency and wear properties of PM gears. Paper A compares the wear, friction, and damage mechanism properties of two sintered gear materials with those of a standard gear material. Paper B deals with the gear mesh torque loss mechanism of PM and regular steel gears by combining both pin-on-disc frictional and FZG efficiency tests. Paper C comparatively examines the efficiency of PM and regular steel gears by conducting FZG gear efficiency tests. Paper D focuses on the wear and friction properties of PM and regular steel gear materials treated using the triboconditioning process. Paper E studies the friction and wear properties attributable to different pore sizes in PM gear materials.    The results indicate that regular steel meshed with PM gear material and PM meshed with PM gear material are good candidate combinations for gear transmissions. This is because the porosities of PM material can lower the friction coefficient while the wear rate can be the same as or even better than that of regular steel contacts. The triboconditioning process enhances the wear resistance and reduces the friction coefficient of the PM gear material. The friction and wear coefficients of PM meshed with PM gear material display increasing trends with increasing pore size. The friction and wear coefficients of regular steel meshed with PM gear material display decreasing trends with increasing pore size. / <p>QC 20160523</p>

Dirt ingress in hydraulic cylinders is one of the sources that leads to pollution of hydraulic systems. There are already several test rigs to investigate external contamination mechanisms. However, until now only the behavior of the whole sealing system was analyzed. A new testing method to understand the dirt particle transport between a reciprocating motioned rod and a wiper is presented. The new approach aims to avoid known issues such as limited reproducibility and long duration. The paper describes the test rig design and operating principle. First measurement results are shown.

Le virus respiratoire syncytial (RSV) est un virus à ARN de polarité négative. Les études démontrent que toute la population sera infectée par ce virus au moins deux fois avant l’âge de 3 ans. Le RSV peut provoquer plusieurs pathologies respiratoires telles que la bronchiolite aiguë et la pneumonie. Les infections sévères corrèlent avec le développement de l’asthme. Lors d’une infection virale, les particules du RSV sont détectées par le senseur RIG-I qui induit l’activation des facteurs de transcription NF-κB et IRF-3. Respectivement, les facteurs de transcription activeront les réponses inflammatoire et antivirale. Au coeur des pathologies induites par le RSV se trouve une réponse immunitaire mal adaptée. Plus précisément, par l’entremise de NF-κB, le RSV provoque une production exagérée de cytokines et chimiokines qui induisent une réponse inflammatoire démesurée provoquant du dommage tissulaire. Paradoxalement, le RSV est capable d’échapper à la réponse antivirale. Ces deux phénomènes sont contrôlés par l’entremise des protéines non structurales NS1 et NS2. Le mécanisme délimitant le mode d’action de NS1 et NS2 sur la réponse antivirale reste à être déterminé. Avec pour objectif d’élucider comment NS1 et NS2 inhibent la réponse antivirale, nous avons investigué le mécanisme de reconnaissance de l’hôte vis-à-vis de RSV. Nous démontrerons, pour la première fois, que le senseur cytosolique MDA5 est impliqué dans la réponse antivirale contre le RSV. Nous présenterons des résultats préliminaires qui suggèrent que le rôle de MDA5 est non redondant à RIG-I. À l’aide d’ARN interférant dirigé contre RIG-I et de transfection de MDA5, nous démontrerons que MDA5 ne contribue pas à la phosphorylation d’IRF-3, mais plutôt qu’elle régit la stabilité du facteur de transcription. Nous démontrerons aussi que, contrairement à l’hypothèse actuelle sur le fonctionnement de NS1 et NS2, l’inhibition de ces derniers ne provoque pas une augmentation de la cytokine antivirale IFN−β. Cependant, l’expression ectopique de NS1 et NS2 réduit l’activité du promoteur de l’IFN-β et de la protéine cytoplasmic antivirale ISG56 lorsqu’elle est mesurée par essai luciférase. / Respiratory Syncytial Virus (RSV) is a RNA virus with negative polarity. RSV infections are the most common cause of hospitalization among infants. Among populations at risk, infection of RSV can be quite severe. RSV infections can cause bronchiolitis, pneumonia, while severe infections are linked to the development of asthma. Early in the infectious cycle of RSV, the cytosolic sensor RIG-I captures viral particles, and activates the immune response by engaging the transcription factors IRF-3 and NF-κB. At the heart of RSV mediated pathologies is a skewed immune response. More precisely, RSV over stimulates the release of proinflammatory chemokines and cytokines. Intriguingly, while RSV is able to stimulate the production of proinflammatory cytokines and chemokines, RSV under stimulates the antiviral response. The ability of RSV to evade the antiviral response is thought to be mediated by its non-structural proteins: NS1 and NS2. However, the mechanism by which NS1 and NS2 enable RSV to evade the antiviral response remains to be determined. In this memoir we investigated, how RSV is recognized by the innate immune response in airway epithelial cells. With this information we hope to improve our understanding of how NS1 and NS2 allow RSV to circumvent the antiviral response. We show for the first time that cytosolic sensor MDA5 plays a role in the recognition of RSV particles. Using a combination of interfering RNA directed against RIG-I, and transfection of MDA5, we show that MDA5 does not contribute to the phosphorylation of IRF-3. According to the data presented, we suggest that MDA5’s role in the immune response is to prevent the degradation of IRF-3. Contrary to previous research, we show that the inhibition of the nonstructural protein does not increase the production of the antiviral cytokine IFN-β. However, the ectopic expression of NS1 and NS2 does lead to a reduction of the promoter activity of IFN-β and the antiviral protein ISG56 when measured by luciferase assay. This research highlights the importance of MDA5 as a potential therapeutic target in the development of a cure for RSV.