Regulation of OPA1 processing and mitochondrial fusion by m-AAA protease isoenzymes and OMA1

m-AAA proteases cleave OPA1 to ensure a balance of long and short OPA1 isoforms, whereas cleavage by OMA1 causes an accumulation of the short OPA1 variants. (See also companion paper from Head et al. in this issue.

Utveckling av nya rotationskoncept för bergborrar

In blast hole drilling, it is desirable to be able to drill as close as possible to the edge of the tunnel. The minimum distance from the edge is defined by the radial size of the rockdrill. Most of the rock drills used today have a rotation motor that rotates an axel parallel to the shank, which further rotates the shank through a gear set. Thus making the rock drill bulky. This thesis project carried out at Atlas Copco Rock Drills AB, Örebro, deals with the rotation mechanism of a rock drill. The main task of the project was to develop alternate concepts for rotation mechanism that would use the shank as a part of rotation mechanism and reduce the bulkiness of the rock drill. In order to find a suitable alternative, eight different concepts for hydraulic motor (with or without transmission) were generated and evaluated against each other. Two concepts, 1) multi-cam vane motor concept and 2) strain wave hydraulic gear motor concept, were selected for further functional design. Both concepts were designed at ideal conditions (100% efficiency) to achieve the required displacement. For the multi-cam vane motor, various design improvements were performed and the effect of different design parameters were also analyzed. Different variants of the motor were developed and analyzed. A rough design was performed for the strain wave hydraulic gear motor concept which was chosen for its novelty. CAD models for both the concepts and the related variants were developed for suggesting assembly layouts and valve mechanisms. The two concept designs would reduce the bulkiness of the rock drill. The benefits and drawbacks of the different variants have been discussed. The concepts must be further developed for implementation into a rockdrill.Vid spränghålsborrning är det önskvärt att borra så nära tunnels periferi som möjligt. Det minsta avståndet från kanten definieras av borrmaskinens radie. Majoriteten av dagens borrmaskiner har en rotationsmotor som roterar en axel parallell till nackadaptern, vilket i sin tur roterar nackadaptern genom en drevuppsättning. Detta gör borrmaskinen otymplig. Detta examensarbete, som utfördes på Atlas Copco Rock Drills AB, Örebro, undersöker rotationsmekanismen hos en borrmaskin. Projektets huvuduppgift var att utveckla alternativa koncept till rotationsmekanismen som använder nackadaptern som en del av rotationsmekanismen och reducerar borrmaskinens otymplighet. För att hitta ett lämpligt alternativ genererades åtta olika koncept för en hydraulisk motor (med och utan transmission) som sedan utvärderades. Två koncept, 1) ”multi-kam vingmotor” och 2) ”hydrauliskt driven töjningsvåg-växel”, valdes för ytterligare funktionell konstruktion. Båda koncepten konstruerades under ideala förhållanden (100% effektivitet) för att uppnå det deplacement som krävs.För ”multi-kam vingmotor” utfördes ett flertal konstruktionsförbättringar och effekten av olika konstruktionsparametrar analyserades. Olika varianter av motorn togs fram samt analyserades. En grov design genomfördes för ”hydrauliskt driven töjningsvåg-växel”, vilken valdes på grund av att designen inte förekommit I någon litteratur. CAD-modeller för båda koncepten samt relaterade varianter togs fram för att föreslå monteringslayouter och ventilmekanismer. De två koncepten skulle reducera otympligheten hos borrmaskinen. För –och nackdelarna hos de olika varianterna har diskuterats. Koncepten måste utvecklas ytterligare för att kunna implementeras i en borrmaskin

Sustainable Lubrication and Tribotronics enabled by Ionic Materials

Developments in machine design play a crucial role in the global endeavor towards sustainability. The potential for energy conservation and emission reduction has pushed lubrication research to the forefront, with the lubricant considered to be a vital machine component. As a result of the need for high machine efficiency and longevity, as well as that of greener lubricants, ionic liquids (ILs) are gaining attention for lubrication applications, especially in combination with biodegradable oils. ILs also present a unique opportunity for developing active lubrication, tribotronic systems. To make them an industrially viable option, however, an in-depth understanding of IL lubrication behavior is required. In this doctoral work, investigations of the tribologically relevant ionic boundary films formed by non-halogenated ILs dispersed in a carrier medium (polar solvent or bio-oil) were conducted using a variety of tribological techniques and neutron reflectance. The effect of external actuation by electric potential on the extent, ionic composition, and tribological relevance of the interfacial boundary films was also studied. The results revealed that the ionic architecture and the condition of IL in the oil play an important role in defining the lubricity of the adsorbed boundary films. Clear electroresponsivity was also observed across methods, with the relative concentration of cations and anions in the interfacial film and the lubricating film thickness changing with the electric potential bias. It was established that the anions, playing an anchor role on the surface, are crucial for the formation of robust load-carrying boundary films. A methodology using electrochemical impedance spectroscopy was developed for measuring and characterizing the electric conductivity of complex lubricating greases with ionic and non-ionic additives. According to these measurements, the electrical characteristics of greases depend on the interactions of IL with the grease matrix. Overall, this work contributes towards the development of sustainable lubrication and tribotronic systems using ILs.Utvecklingen inom ämnesområdet maskinkonstruktion spelar en avgörande roll i den globala strävan mot hållbarhet. Potentialer för energibesparing och utsläppsminskningar har drivit på forskningen om smörjmedel och smörjmedlet anses idag vara ett viktigt maskinelement. Som ett resultat av behovet av hög verkningsgrad, lång livslängd samt miljövänligare smörjmedel, har jonvätskor (eng. Ionic Liquids) fått uppmärksamhet inom smörjtillämpningar, särskilt i kombination med biologiskt nedbrytbara oljor. Jonvätskor ger även en unik möjlighet att utveckla tribotroniska system för aktiv smörjning. För att göra dem industriellt gångbara krävs dock en djupgående förståelse för jonvätskors smörjegenskaper. Inom ramen för detta doktorandprojekt genomfördes undersökningar av de smörjfilmer som bildas i kontakters gränssnitt av icke-halogenerade jonvätskor dispergerade i ett polärt lösningsmedel eller en bioolja. En mängd olika tribologiska mätinstument, bland annat neutronreflektans, användes i projektet. Smörjfilmens egenskaper under inverkan av en extern aktivering via en elektrisk potential studerades även genom att mäta filmtjocklek, jonsammansättning samt tribologisk relevans i gränsskikten. Resultaten visade att den joniska arkitekturen och tillståndet för jonvätskan i oljan spelar en viktig roll för att definiera smörjförmågan hos de adsorberade gränsfilmerna. Tydliga reaktioner på en pålagd elektrisk potential observerades genom att mäta förändringar av den relativa koncentrationen av katjoner och anjoner i gränssnittsfilmen samt smörjfilmens tjocklek. Det konstaterades att anjonerna, som fungerar som ankare på ytan, är avgörande för bildandet av robusta lastbärande gränsfilmer. En metodik som använder elektrokemisk impedansspektroskopi utvecklades för att mäta och karakterisera den elektriska ledningsförmågan hos komplexa smörjfetter med joniska och icke-joniska tillsatser. Enligt dessa mätningar beror fetters elektriska egenskaper på interaktionen mellan jonvätskan och fettmatrisen. Sammantaget bidrar detta arbete till utvecklingen av hållbara smörjmedel samt tribotroniska system där jonvätskor används

Characteristics and risk factors associated with work zone crashes

Master of ScienceDepartment of Civil EngineeringSunanda DissanayakeIn the United States, approximately 1,100 people die and 40,000 people are injured annually as a result of motor vehicle crashes in work zones. These numbers may be a result of interruption to regular traffic flow caused by closed traffic lanes, poor traffic management within work zones, general misunderstanding of problems associated with work zones, or improper usage of traffic control devices. In regard to safety of work zones, this study was conducted to identify characteristics and risk factors associated with work zone crashes in Iowa, Kansas, Missouri, Nebraska and Wisconsin, states currently included in the Smart Work Zone Deployment Initiative (SWZDI) region. The study was conducted in two stages. In the first stage, characteristics and contributory causes related to work zone crashes such as environmental conditions, vehicles, crashes, drivers, and roadways were analyzed for the five states for the period 2002-2006. An analysis of percentage-wise distributions was carried out for each variable based on different conditions. Results showed that most of the work zone crashes occurred under clear environmental conditions as during daylight, no adverse weather, etc. Multiple-vehicle crashes were more predominant than single-vehicle crashes in work zone crashes. Primary driver-contributing factors of work zone crashes were inattentive driving, following too close for conditions, failure to yield right of way, driving too fast for conditions, and exceeding posted speed limits within work zones. A test of independency was performed to find the relation between crash severity and other work zone variables for the combined states. In the second stage, a statistical model was developed to identify risk factors associated with work zone crashes. In order to predict injury severity of work zone crashes, an ordered probit model analysis was carried out using the Iowa work zone crash database. According to findings of the severity model, work zone crashes involving trucks, light duty vehicles, vehicles following too close, sideswipe collisions of same-direction vehicles, nondeployment of airbags, and driver age are some of the contributing factors towards more severe crashes

Molekulare Charakterisierung des Optischen Atrophie Proteins OPA1

Title Table of contents Summary i Zusammenfassung ii 1\. Introduction 1 2\. Materials 17 3 Methods 23 4\. Results 39 5\. Discussion 63 6\. References 75 7\. Appendix 83The mitochondrion is an essential cytoplasmic organelle that provides most of the energy necessary for a eukaryotic cell. Mitochondrial structure and functions are maintained by proteins of both mitochondrial and nuclear origin. The entire mitochondrial population is in constant flux, driven by continual fusion and division of mitochondria. Defects in mitochondrial dynamics can cause deficits in mitochondrial respiration, morphology and motility leading to apoptosis under extreme conditions. Mutations in OPA1, a nuclear encoded mitochondrial protein, involved in the mitochondrial fusion mechanism cause autosomal dominant optic atrophy. OPA1 is expressed as eight mRNA splice variants in human cells generated by alternative splicing of exons 4, 4b and 5b (Delettre et al., 2001). This study was undertaken to characterize the mouse OPA1 GTPase. Four mRNA splice variants 1, 5, 7 and 8, were found in mouse tissues generated by alternative splicing of exons 4b and 5b. In contrast to an earlier report, alternative splicing of exon 4 was not confirmed. While the overall level of OPA1 gene transcription seems to be constant throughout tissues, the individual expression level of the four splice variants in the mouse brain differs when compared to other tissues, indicating the existence of a post-transcriptional regulatory mechanism. Particularly, splice form 1 was predominantly expressed in the mouse brain. To study the expression of OPA1 protein isoforms, monoclonal antibodies were generated that identified six protein isoforms on western blots. Mass spectrometry and N-terminal microsequencing revealed the two longest forms to be OPA1 isoforms 1 and 7 which are cleaved by mitochondrial processing peptidase (MPP) during protein import into mitochondria. Furthermore, post-MPP processing by other unknown proteases in regions corresponding to exons 5, 5b and 6 generated three different short forms of OPA1. Only the long forms were tightly embedded into the mitochondrial inner membrane, whereas the short forms were extracted easily from the membranes presumably due to the loss of the transmembrane domain after post-MPP processing. The expression levels of OPA1 protein isoforms varied in a tissue dependent manner, though all the tissues contained identical set of isoforms. OPA1 isoform 1 was predominant in mouse nervous tissues. Gel filtration experiments showed that the longest of the three short forms distinctly formed a dimer of 184-kDa while all other OPA1 protein isoforms were part of a 285-kDa complex. The two coiled-coil domains present in the OPA1 protein isoforms showed a high affinity to self- associate (but not to hetero-associate) that likely mediated the complex formation. Yeast Two-Hybrid screens, co-immunoprecipitation and size exclusion chromatography experiments failed to identify proteins interacting with OPA1.Mitochondrien sind essentielle, cytoplasmatische Organelle, die den Hauptanteil der Energie generieren, den eine eukaryontischen Zelle benötigt. Die Struktur und Funktion der Mitochondrien wird durch mitochondrial- und kernkodierte Proteine aufrechterhalten. Die gesamte Mitochondrienpopulation einer Zelle befindet sichin einem konstanten Flux, der durch permanente Fusions- und Teilungsvorgänge dieser Organellen in Gang gehalten wird. Defekte in dieser Dynamik können Defizite in der Respiration, Morphologie und Beweglichkeit der Mitochondrien verursachen, die im Extremfall sogar zur Apoptose führen. Mutationen in OPA1, einem kernkodierten mitochondrialen Protein, welches in mitochondriale Fusionsprozesse involviert ist, können der Grund zur Ausprägung einer autosomal dominant erblichen Optikusatrophie sein. Die Expression des OPA1 Gens resultiert in 8 verschiedenen Spleissvarianten in humanen Zellen, die durch alternatives Spleissing der Exons 4, 4b und 5b entstehen (Delettre et al., 2001). Die vorliegende Studie befasst sich mit der Charakterisierung der OPA1 GTPase aus der Maus. Vier mRNA Spleissvarianten (1, 5, 7 und 8) wurden in Mausgewebe nachgewiesen, die durch alternatives Spleissing der Exons 4b und 5b entstehen. Im Gegensatz zu der oben genannten Veröffentlichung, wurde alternatives Spleissing von Exon 4 nicht bestätigt. Obwohl der generelle Level an OPA1 Gentranskription in vielen Geweben konstant zu sein scheint, unterscheidet sich das individuelle Expressionsniveau der 4 verschiedenen Spleissvarianten im Maushirn von den Niveaus in anderen Geweben. Dieser Befund deutet auf die Existenz eines post-transkriptionellen Regulationsmecha-nismusses hin. Eine besonders starke Expression der Spleissform 1 im Maushirn wurde festgestellt. Um die Expression von OPA1 Proteinisoformen studieren zu können, wurden monoklonale Antikörper hergestellt, die 6 verschiedene Proteinisoformen im western blot identifizierten. Massenspektroskopische Analysen und N-terminale Mikrosequenzie-rung zeigten, das es sich bei den beiden grössten OPA1 Formen um die OPA1 Isoformen 1 und 7 handelt, die durch die Mitochondriale Prozessierungspeptidase (MPP) während des mitochondrialen Proteinimports gespalten werden. Post-MPP Prozessierungsvor-gänge, die durch bisher unbekannte Proteasen in den Regionen ausgeführt werden, die von den Exons 5, 5b und 6 kodiert werden, lassen drei verschiedene kurze Formen von OPA1 entstehen. Diese kurzen Formen können leicht von mitochondrialen Membranen extrahiert werden, da sie ihre Transmembrandomäne nach der Post-MPP- Prozessierung verloren haben. Nur die langen OPA1 Polypeptide sind stabil in der inneren Mitochondrienmembran verankert. Obwohl die Expressionsnivieaus der OPA1 Proteinisoformen gewebespezifisch variieren, enthalten alle ii Zusammenfassung Gewebe das gleiche Set an Isoformen. Isoform1 war auch auf Proteinebene im Nervengewebe der Maus am stärksten exprimiert. Gelfiltrationsexperimente zeigten, dass die grösste der drei kurzen Formen einen Dimer von 184-kDa Grösse bildet, während alle anderen OPA1 Isoformen Teil eines 285-kDa Komplexes waren. Zwei Coiled-coil-Domänen des OPA1 Proteins zeigten eine hohe Affinität für Homo-Assoziation, gingen aber keine Hetero- Interaktionen ein. Sie tragen sehr wahrscheinlich zu der Komplexformation der OPA1 Moleküle bei

Sustainable Lubrication and Tribotronics enabled by Ionic Materials

Developments in machine design play a crucial role in the global endeavor towards sustainability. The potential for energy conservation and emission reduction has pushed lubrication research to the forefront, with the lubricant considered to be a vital machine component. As a result of the need for high machine efficiency and longevity, as well as that of greener lubricants, ionic liquids (ILs) are gaining attention for lubrication applications, especially in combination with biodegradable oils. ILs also present a unique opportunity for developing active lubrication, tribotronic systems. To make them an industrially viable option, however, an in-depth understanding of IL lubrication behavior is required. In this doctoral work, investigations of the tribologically relevant ionic boundary films formed by non-halogenated ILs dispersed in a carrier medium (polar solvent or bio-oil) were conducted using a variety of tribological techniques and neutron reflectance. The effect of external actuation by electric potential on the extent, ionic composition, and tribological relevance of the interfacial boundary films was also studied. The results revealed that the ionic architecture and the condition of IL in the oil play an important role in defining the lubricity of the adsorbed boundary films. Clear electroresponsivity was also observed across methods, with the relative concentration of cations and anions in the interfacial film and the lubricating film thickness changing with the electric potential bias. It was established that the anions, playing an anchor role on the surface, are crucial for the formation of robust load-carrying boundary films. A methodology using electrochemical impedance spectroscopy was developed for measuring and characterizing the electric conductivity of complex lubricating greases with ionic and non-ionic additives. According to these measurements, the electrical characteristics of greases depend on the interactions of IL with the grease matrix. Overall, this work contributes towards the development of sustainable lubrication and tribotronic systems using ILs.Utvecklingen inom ämnesområdet maskinkonstruktion spelar en avgörande roll i den globala strävan mot hållbarhet. Potentialer för energibesparing och utsläppsminskningar har drivit på forskningen om smörjmedel och smörjmedlet anses idag vara ett viktigt maskinelement. Som ett resultat av behovet av hög verkningsgrad, lång livslängd samt miljövänligare smörjmedel, har jonvätskor (eng. Ionic Liquids) fått uppmärksamhet inom smörjtillämpningar, särskilt i kombination med biologiskt nedbrytbara oljor. Jonvätskor ger även en unik möjlighet att utveckla tribotroniska system för aktiv smörjning. För att göra dem industriellt gångbara krävs dock en djupgående förståelse för jonvätskors smörjegenskaper. Inom ramen för detta doktorandprojekt genomfördes undersökningar av de smörjfilmer som bildas i kontakters gränssnitt av icke-halogenerade jonvätskor dispergerade i ett polärt lösningsmedel eller en bioolja. En mängd olika tribologiska mätinstument, bland annat neutronreflektans, användes i projektet. Smörjfilmens egenskaper under inverkan av en extern aktivering via en elektrisk potential studerades även genom att mäta filmtjocklek, jonsammansättning samt tribologisk relevans i gränsskikten. Resultaten visade att den joniska arkitekturen och tillståndet för jonvätskan i oljan spelar en viktig roll för att definiera smörjförmågan hos de adsorberade gränsfilmerna. Tydliga reaktioner på en pålagd elektrisk potential observerades genom att mäta förändringar av den relativa koncentrationen av katjoner och anjoner i gränssnittsfilmen samt smörjfilmens tjocklek. Det konstaterades att anjonerna, som fungerar som ankare på ytan, är avgörande för bildandet av robusta lastbärande gränsfilmer. En metodik som använder elektrokemisk impedansspektroskopi utvecklades för att mäta och karakterisera den elektriska ledningsförmågan hos komplexa smörjfetter med joniska och icke-joniska tillsatser. Enligt dessa mätningar beror fetters elektriska egenskaper på interaktionen mellan jonvätskan och fettmatrisen. Sammantaget bidrar detta arbete till utvecklingen av hållbara smörjmedel samt tribotroniska system där jonvätskor används

Electron beam evaporated gold doped tungsten oxide nanostructured films for sensor applications

Gas sensors play a vital role in monitoring environmental pollution for human health, safety, and the detection of various gasses in the environment. Nanostructured metal oxide thin films have been widely used in sensor applications owing to their unique properties. In this study, pure and gold (Au) doped nanostructured tungsten trioxide (WO3) films were deposited on glass substrates by electron beam evaporation at room temperature. The microstructure of the WO3 films changed from nanoflakes to nanorods upon variation of the wt% of Au. The sensing properties of WO3 based nanostructure films were measured using a computer-controlled system. The gas sensing results showed that the Au-doped WO3 films exhibited a higher sensitivity than the undoped films. The 15 wt% Au-doped WO3 nanostructure films showed high sensitivity towards ethanol and the response (sensitivity) value was 89. The response and recovery times for 15 wt% Au-doped WO3 were 8 and 10 s, respectively

EMPIRICAL STUDY: LEADERSHIP, ORGANIZATION CULTURE, EMPLOYEE ENGAGEMENT IN INFORMATION TECHNOLOGY CONTINUOUS IMPROVEMENT ADOPTION: Received: 10th May 2023; Revised: 26th September 2023, 25th October 2023; Accepted: 01st November 2023

Continuous Improvements (CI) is well-known for its significance in driving and facilitating process and products improvements in organizations. For decades, large organizations used CI to improve and streamline process and workforce. CI thinking and adoption is critical for IT functions to improve aspects such as innovation, team productivity, service reliability, and cost optimization. The role of organization culture, leadership, employee engagement become key for adoption of CI to ensure stability, scalability, and sustainability to business functions through right tools, technologies, and services. There is need for research on the influence of trio on adoption of CI in the context of IT. The trio are interrelated components that play a crucial role in the success and sustainability of any organization. The aim of this study is to evaluate these three factors, its influence on adoption of CI by IT function using a quantitative approach. This study engages IT stakeholders from ITES, global companies which have their global IT development centres in India to ascertain their views. The finding of the study shows organization culture has a strong influence on adoption of CI in IT. This study can provide critical insights to management in streamlining IT practice, design organization mechanisms for better adoption of CI in IT

Tribotronic control of an ionic boundary layer in operando extends the limits of lubrication

Abstract The effect of electric potential on the lubrication of a non-halogenated phosphonium orthoborate ionic liquid used as an additive in a biodegradable oil was studied. An in-house tribotronic system was built around an instrument designed to measure lubricant film thickness between a rolling steel ball and a rotating silica-coated glass disc. The application of an electric field between the steel ball and a set of customized counter-electrodes clearly induced changes in the thickness of the lubricant film: a marked decrease at negative potentials and an increase at positive potentials. Complementary neutron reflectivity studies demonstrated the intrinsic electroresponsivity of the adsorbate: this was performed on a gold-coated silicon block and made possible in the same lubricant system by deuterating the oil. The results indicate that the anions, acting as anchors for the adsorbed film on the steel surface, are instrumental in the formation of thick and robust lubricating ionic boundary films. The application of a high positive potential, outside the electrochemical window, resulted in an enormous boost to film thickness, implicating the formation of ionic multi-layers and demonstrating the plausibility of remote control of failing contacts in inaccessible machinery, such as offshore wind and wave power installations