1,492 research outputs found
Data and Code for 'A Reevaluation of the Effect of Dietary Restriction on Different Recombinant Inbred (RI) Lines of Male and Female Mice'
No full textData and Code Sharing for Unnikrishnan A, Matyi S, Garrett K, Ranjo-Bishop M, Allison DB, Ejima K, Chen X, Dickinson S, Richardson A. Reevaluation of the effect of dietary restriction on different recombinant inbred lines of male and female mice. Aging Cell. 2021 Nov;20(11):e13500. doi: 10.1111/acel.13500. Epub 2021 Oct 29. Erratum in: Aging Cell. 2022 Jan;21(1):e13534. PMID: 34713968; PMCID: PMC8590105. https://pubmed.ncbi.nlm.nih.gov/34713968
Data and Code for 'A Reevaluation of the Effect of Dietary Restriction on Different Recombinant Inbred (RI) Lines of Male and Female Mice'
No full textData and Code Sharing for Unnikrishnan A, Matyi S, Garrett K, Ranjo-Bishop M, Allison DB, Ejima K, Chen X, Dickinson S, Richardson A. Reevaluation of the effect of dietary restriction on different recombinant inbred lines of male and female mice. Aging Cell. 2021 Nov;20(11):e13500. doi: 10.1111/acel.13500. Epub 2021 Oct 29. Erratum in: Aging Cell. 2022 Jan;21(1):e13534. PMID: 34713968; PMCID: PMC8590105. https://pubmed.ncbi.nlm.nih.gov/34713968
Data and Code for 'A Reevaluation of the Effect of Dietary Restriction on Different Recombinant Inbred (RI) Lines of Male and Female Mice'
No full textData and Code Sharing for Unnikrishnan A, Matyi S, Garrett K, Ranjo-Bishop M, Allison DB, Ejima K, Chen X, Dickinson S, Richardson A. Reevaluation of the effect of dietary restriction on different recombinant inbred lines of male and female mice. Aging Cell. 2021 Nov;20(11):e13500. doi: 10.1111/acel.13500. Epub 2021 Oct 29. Erratum in: Aging Cell. 2022 Jan;21(1):e13534. PMID: 34713968; PMCID: PMC8590105. https://pubmed.ncbi.nlm.nih.gov/34713968
Research project work plan for trends and challenges posed by medium-duty trucks to the operation and safety of Oregon highways
No full textsubmitted by Salvador Hernandez, (Associate Professor (PI)), Oregon State University and Avinash Unnikrishnan, (Associate Professor (Co-PI)), Miguel Figliozzi, (Professor (Co-PI)), Portland State University for Oregon Department of Transportation, Research Unit.Title from PDF title page (viewed on October 28, 2020)."SPR-846."This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Mode of access: Internet from the Oregon Government Publications Collection.Text in English.Covers OCLC #120214963
Impact of truck platooning on loading of bridges in Oregon
No full textsubmitted by Michael Scott, Professor (PI), Oregon State University and Thomas Schumacher, Associate Professor (Co-PI), Avinash Unnikrishnan, Associate Professor (Co-PI), Portland State University for Oregon Department of Transportation, Research Unit.Title from PDF title page (viewed on October 28, 2020)."SPR-848."This archived document is maintained by the State Library of Oregon as part of the Oregon Documents Depository Program. It is for informational purposes and may not be suitable for legal purposes.Mode of access: Internet from the Oregon Government Publications Collection.Text in English.Covers OCLC #120215050
Implications of nanoparticle-protein interactions on protein assembly and conformation
No full textSubmission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2026-08-01The student, Mahima Unnikrishnan, accepted the attached license on 2024-07-08 at 09:30.The student, Mahima Unnikrishnan, submitted this Dissertation for approval on 2024-07-08 at 10:13.This Dissertation was approved for publication on 2024-07-10 at 15:54.DSpace SAF Submission Ingestion Package generated from Vireo submission #20977 on 2025-02-04 at 21:25:35The interaction between nanoparticles and proteins presents a promising avenue for designing nanoparticulate theranostic and diagnostic agents in the biomedical field. Upon entering the body, it is not the as-synthesized nanoparticles, but biomolecule-coated nanoparticles that dictate their function and therapeutic response. By regulating the composition of protein corona on the particles, it becomes possible to conceal the nanoparticle surface and facilitate specific biological functions. Although some fundamental principles guiding interactions between nanoparticles and proteins have been established and accepted by the scientific community, there is ongoing debate regarding the development of a universally applicable theoretical framework for understanding the protein corona due to missing pieces in the puzzle. The work presented in this thesis aims to expand the current understanding of how nanoparticles can alter protein self-assembly and conformation using colloidal inorganic nanoparticles as a platform for corona formation. Chapter 1 covers how nanomaterials came to be popular in the biomedical field and why studying the molecular mechanisms underlying nanoparticle-protein interactions can significantly contribute to successful translation of in vitro findings to in vivo settings. Dynamic nature of the protein corona and the many analytical techniques used for its characterization are discussed. An overview of changes in protein conformation and activity upon adsorption to a nanoparticle surface, its correlation to various biophysicochemical properties governing the nano-bio interface, and the current research challenges associated with the field are also discussed. Chapter 2 presents a systematic investigation of the effect of unfunctionalized silica nanoparticles on the self-assembly of a bacterial tubulin protein pair in buffer, in cell lysate, and in a living mammalian cell using Förster resonance energy transfer. The common assumption that nanoparticle-biomolecular interactions that are studied intensively in vitro are good predictors of in vivo activity are shown to be invalid in the case of protein assembly of bacterial tubulins. In buffer, silica nanoparticles promote the complex formation of tubulin proteins as a function of nanoparticle concentration. However, upon microinjection of these tubulins into live cells, nanoparticles at similar concentration have no effect on protein assembly, confirming the environment-dependence of corona formation. In chapter 3, conformational changes in soft corona proteins incubated with gold nanoparticles in buffer are explored; the overarching research problem addressed being ‘can transient interactions with nanoparticles induce permanent protein denaturation?’. In the first part of the chapter, interaction of cationic polymer-wrapped nanoparticles with superoxide dismutase is discussed, while the latter portion of the chapter describes studies performed with chymotrypsin and serum albumin proteins exposed to anionic nanoparticles. Interferences in data due to protein interaction with the free ligand as well as the solid-liquid or air-liquid interfaces during the incubation step, and not weak protein-nanoparticle interactions, were identified as the key factors contributing to results from these studies
Capulopsyche keralensis Unnikrishnan & Sobczyk & Jose & Jose 2023, sp. nov.
No full text<i>Capulopsyche keralensis</i> sp. nov. <p>(Figs. 1–10)</p> <p> <b>Type material.</b> <b>Holotype,</b> ♂ India, Kerala, Idukki, Nariyampara, 9.7424° N, 77.0939° E, 28.xi.2022, with larval case, leg. Usha A U (Fig. 1). Holotype will be deposited at the Zoological Survey of India Museum, Calicut, Kerala after submission of thesis of the first author and is at present at St. Thomas College, Thrissur.</p> <p> <b>Paratypes:</b> 2 ♀, (both with larval case) same data as holotype, 16.xii.2021, leg. Usha, A. U. (Fig. 2 a–b); 2♂ (both with larval case) same data as holotype, 30.xi.2022, leg. Usha, A. U.; additional 24 larval cases with pupal exuviae, same data as paratypes, leg. Usha, A. U.; 4 larval cases with pupal exuviae, Nelliyampathy, Palakkad, Kerala, 10.5013° N, 76.6768° E, 15.ii.2022, leg. Usha, A. U. (Figs. 2 a–b).</p> <p> <b>Diagnosis.</b> See the diagnosis for the genus.</p> <p> <b>Etymology.</b> The specific epithet <i>keralensis</i> is derived from the state of Kerala in India. The binomial <i>Capulopsyche keralensis</i> means ‘coffee psychid of Kerala’.</p> <p> <b>Description. Male</b>. Small-sized brownish black moth, wingspan 8–8.4 mm, body length 2.9 mm, forewing length 3.7mm including fringes, width 1.4 mm.</p> <p> <i>Head</i>. Vestiture yellowish brown, the base of the antennae thickly covered with dark yellowish-brown scales with bidentate apices. Antennae total length 1.7 mm, flagellomeres with 24 segments (Fig. 3). EI 1.13 mm.</p> <p> <i>Thorax</i>. Reddish brown, barely covered with scales on the dorsal side. Forewings covered with dark brown scales mixed with yellowish scales (Fig. 4). Scales broad (class 5–6), with 5-8 tips. The darker scales are mainly in the area of the front and outer margin and are partly arranged in irregular transverse bands. Fringes dark, wide, multi-pointed Hindwings dark greyish brown (Fig. 4), slightly lighter at the base. Width 1.4 mm, WI 2.6 mm. Wing venation as described for genus (Figs 5 a–b).</p> <p> <i>Abdomen</i>. Small, covered with blackish scales, length 1.6 mm.</p> <p> <i>Leg</i>. As described for the genus (Figs 6 a–c).</p> <p> <i>Genitalia</i>. Length 0.46 mm. Valva broad, curved inwardly, surmounting the posterior border of the tegumen, rounded distally, with numerous setae. Sacculus attached basally, ending in a strong curved spine. Phallus short, tubular, length 0.23 mm. (Fig. 7).</p> <p> <i>Female.</i> Length 2.5–3 mm. Body pale yellowish, around the abdomen loosely covered with very narrow, distally rounded brownish black scales. Eyes are very small, EI 2.3 mm. Legs short, reduced. Femur and tibia present, tarsi reduced to 2-3 segments, with two prominent claws, pale yellowish brown. Antenna short, filiform, 0.5 mm long, with 6-9 different scaled segments. The two basal segments are wider than the others. The distal end of the abdomen with long ovipositor, surrounded by an anal hair-tuft consisting of long golden-brown hairlike scales.</p> <p> <i>Larva</i>. (Fig. 8a and b) Body whitish cream, head distinctly sclerotized, first and second thoracic segment dark brown, strongly sclerotized dorsally, third thoracic segment more strongly sclerotized at the posterior margin. The abdominal segments were without sclerotized fields, the anal shield only slightly more sclerotized. Fully grown larva 4 mm in length.</p> <p> <i>Male and female pupal exuvia</i>. (Figs. 9 a–b) Dark golden-brown, male exuvia 3.0– 3.5mm in length and 1 mm in width, female exuvia 3.8–4.0 mm in length and 1.5 mm in width.</p> <p>A single row of spines dorsally on abdominal segments IV-VIII. The spines are directed backwards. Each row is comb-like and with numerous tiny hair-like spines. These spines probably serve to fix the pupa, and later to move it towards the exit and to hold it in place during emergence. In female pupae, the spines are shorter and reduced.</p> <p> <i>Larval case</i>. (Figs. 10 a–b) The larval case of this species is an elongated tube-like, wrapped with a sheath made up of bark tissues from the trees. An adult male case has a length of 12–13 mm, and the width of the outer sheath is 5–6 mm. Female case has a 15–16 mm length and 6–7 mm width, and the attached thread of each case is 7–9 mm long. Double-walled larval cases reported from Psychidae are the triangular larval cases of <i>Diplodoma</i> Zeller, 1852 which also hung up on threads. But in <i>Diplodoma</i>, the inner case has a distinctive triangular shape and is not visible from the outside. The outer case also has a triangular basic shape in cross-section.</p> <p> <b>Distribution.</b> Larval and pupal cases were collected from the coffee plantations of two localities from Kerala state, Nariyampara and Nelliyampathy of Idukki and Palakkad districts (Fig. 11) respectively. Pupal cases were seen hung on the twigs and und <i>er</i> side of leaves of the <i>Coffea arabica</i> plant (Fig. 12).Altitude at the sites of the collection was 960 m and 887 mASL. Both collection sites were situated inside private coffee plantations. The soil type of the region is described as ‘Clayey mixed ustic pale humults and rock land(very deep,well-drained,clayey soil on moderately steeply sloping high hills with thin vegetation, with moderate erosion, associated with rock outcrops and deep well-drained gravelly loam soils on gentle slopes) in Soil Maps of India (1996). In Nelliyampathy the summer temperature ranges from 20°C to 33°C and in winter15°C to28°C. In Nariyampara the average temperature is20°C.Summer temperatures range from 19°C to 29°C and winter temperatures are in the range of 15°C to 24°C. Average rainfall according to Centre for Earth Studies Resource Atlas of Kerala (1984) for South West Monsoon is 150 cm at Nariyampara and 250 cm at Nelliyampathy. For both sites, Northeast Monsoon was 40 cm and ‘Other rains’ was reported as 30–50 cm.</p> <p> <b>Biology.</b> The larvae of this species were found scraping on the bark of trees, they seem to feed on the bark tissues and depositions (algae) on the bark. The pupal cases are attached by a thread to the branches and underside of the leaves of plants (Fig. 12).</p> <p>The life span of an emerged male adult was up to 4 to 5 days. There are many eggs wrapped with silken cases were seen inside the female cases, and female adults lay eggs using their ovipositor inside the case after mating. Each yellow-coloured egg was found wrapped inside loosely spun silken cocoons. Eggs clustered together to form a group egg mass (Fig. 13) inside the sheath of the case. The larval case is made of silk and covered with bark tissues, and other substances present in the bark.</p> <p> <b>DNA barcode and phylogenetic analysis.</b> COI sequencing of the species collected from the two locations Nariyampara and Nelliyampathy was done and the sequences have 641 and 654 base pairs respectively. The sequences were uploaded in the NCBI GenBank with the accession numbers OP960232 and OP957497.</p> <p> The evolutionary relationship is depicted in the tree with the highest log likelihood (-3908,46) (Fig. 14). Based on the tree constructed using these two COI genes and other available species from GenBank and BOLD SYSTEMS, a hypothetical taxonomic unit representing a Taleporiinae ancestor splits into two branches with three genera <i>Bankesia</i>, <i>Pseudobankesia</i>, and <i>Taleporia</i> forming one group and <i>Sciopetris melitensis</i> forming the second group with <i>Capulopsyche keralensis</i> <b>gen. et sp. nov.</b>. The distance between <i>S. melitensis</i> and <i>Capulopsyche keralensis</i> <b>gen. et sp. nov.</b> indicates that they are two distinct species. In addition <i>S. melitensis</i> is a Mediterranean palaearctic species.</p>Published as part of <i>Unnikrishnan, Usha Ayyath, Sobczyk, Thomas, Jose, Roby Thekkudan & Jose, Joyce, 2023, Capulopsyche keralensis gen. et sp. nov., a new genus and species of the subfamily Taleporiinae (Lepidoptera: Psychidae) from Kerala, India, pp. 270-284 in Zootaxa 5258 (3)</i> on pages 272-282, DOI: 10.11646/zootaxa.5258.3.2, <a href="http://zenodo.org/record/7780180">http://zenodo.org/record/7780180</a>
Cooling, transport and mixing of ultracold K and Cs
No full textSeit den frühen 1980er Jahren gibt es Vorschläge, große quantenmechanische Systeme zu untersuchen, die für klassische Computer unzugänglich sind, indem sie direkt über ein anderes gut kontrolliertes Quantensystem simuliert werden. Das Aufkommen von Quantengasexperimenten, die auf bahnbrechenden Fortschritten bei der Laserkühlung und dem Einfangen von Atomen aufbauen, beispielhaft dargestellt durch die erste Realisierung eines quantenentarteten Gases im Jahr 1995, hat danach zu einem ganzen Spektrum experimenteller Bemühungen geführt, um hochgradig kontrollierbare Quantensysteme zu realisieren, die zur Durchführung von Quantensimulationen verwendet werden können. Unter den verschiedenen möglichen Plattformen sind polare Bialkali-Moleküle besonders interessant, da sie über abstimmbare, langreichweitige Dipol-Dipol-Wechselwirkungen interagieren. In Kombination mit kürzlich entwickelten Werkzeugen, die eine ortsaufgelöste Abbildung und Adressierung von gittergebundenen Atomen ermöglichen, stellt ein solches System ein vielseitiges Werkzeug zur Untersuchung verschiedener Quantenphänomene bereit. Diese Dissertation konzentriert sich auf die Realisierung mehrerer wichtiger Schritte zur Realisierung eines solchen Quanten-Toolkits unter Verwendung von K- und Cs-Atomen.
Die hochauflösende Abbildung von Atomen, die in einem Gitter gefangen sind, benutzt das Prinzip der Laserkühlung, um zu verhindern, dass die Atome zwischen Gitterstellen tunneln, während das gestreute Licht aufgesammelt wird. Die Auflösung eines solchen Abbildungssystems ist direkt proportional zur Wellenlänge des für die Laserkühlung verwendeten Lichts. In diesem Zusammenhang demonstrieren wir eine Sub-Doppler-Laserkühlung von 39 K unter Verwendung einer entarteten Raman-Seitenbandkühlung über den 4S1/2 5P1/2-Übergang bei 404,8 nm. Im Gegensatz zu den Standard-Laserkühltechniken, die auf den D2- und D1-Übergängen beruhen, wird hier ein hochangeregtes Niveau in den Kühlzyklus integriert.
Die hochauflösende Abbildung kalter Atome erfordert einen guten optischen Zugang. Es liegt daher nahe, den Ort der Erzeugung des Quantengases und die eigentliche Experimentierkammer räumlich zu trennen. Allerdings braucht es dann einen Transport der ultrakalten Atome. Wir stellen mehrere Ansätze und die damit verbundenen Herausforderungen bei der Entwicklung eines geeigneten Transportsystems für unser Experiment vor und schließen mit der Entwicklung eines neuen, auf Moiré-Linsen basierenden, kompakten und robusten Aufbaus, um ultrakalte Atome optisch über große Entfernungen zu transportieren.
Eine Beschreibung der Weiterentwicklung eines parallelen Mischschemas zur Herstellung ultrakalter K-Cs-Mischungen, das den experimentellen Ablauf und Aufwand deutlich vereinfachen soll, wird nachfolgend diskutiert. Zusätzlich wird die Entwicklung einer neuen Experimentierkammer beschrieben. Eine neue solche Kammer ist erforderlich geworden, da in der bestehenden die Vakuumqualität nicht ausreicht. Gleichzeitig gelingt es damit, die Anforderungen an optischem Zugang und Kontrolle des elektrischen Feldes optimal zu erfüllen.
Abschließend wird eine Zusammenfassung der Arbeiten zur Untersuchung der Bandstruktur des Kagome-Gitters präsentiert. Diese Arbeit wurde während eines Forschungsaufenthalts an der University of California, Berkeley, durchgeführt, der durch das Doktoratskolleg "Atoms, Light, and Molecules" in Innsbruck ermöglicht wurde.Proposals to study large quantum mechanical systems that are intractable to classical computers by directly simulating them via another well controlled quantum system have existed since the early 1980s. The emergence of quantum gas experiments building upon pioneering advances in laser cooling and trapping of atoms, exemplified by the first realization of a quantum degenerate gas in 1995, has thereafter given rise to an entire spectrum of experimental efforts to realize highly controllable quantum systems that can be used to carry out quantum simulations. Among the various possible platforms, bialkali polar molecules are especially interesting since they interact via tuneable, long-range dipole-dipole interactions. Combined with more recently developed tools that allow imaging and addressing of lattice bound atoms in a site resolved manner, such a system provides a versatile toolkit to study various quantum phenomena. This thesis is focused on the realization of several important steps towards the realization of such a quantum toolkit using K and Cs atoms.
High resolution imaging of atoms trapped within a lattice relies on laser cooling to prevent the atoms from tunneling between lattices sites, and collecting the light scattered during this process. The resolution of such an imaging system is directly proportional to the wavelength of the light used for laser cooling. In this context, we demonstrate sub-Doppler laser cooling of 39K using degenerate Raman sideband cooling via the 4S1/2 5P1/2 transition at 404.8 nm in contrast to standard laser cooling techniques which rely on the D2 and D1 transitions, where largely closed transition cycles are available.
High resolution imaging of cold atoms require large optical access, which is often met by transporting atoms into a dedicated vacuum chamber containing in-vacuum optics. We present several approaches and the associated challenges in developing a suitable transport system for our experiment, concluding with the development of a new, moiré lens based, compact and robust setup to optically transport ultracold atoms over long distances.
A description of the ongoing development of a parallel mixing scheme for producing ultracold KCs mixtures, which is designed to significantly simplify the experimental sequence and complexity, is provided in Chapter 5. In addition, in view of the compromised vacuum quality in the glass cell meant for high resolution imaging and breakthrough developments in the field that allow robust control over polar molecules by utilizing electric fields generated using specialized infrastructure, a new experimental chamber is being built. We present the design considerations of the most important aspects of the new setup in Chapter 6.
Finally, a summary of the work done on studying the band structure of the Kagome lattice is presented. This work was carried out during a research stay at the University of California, Berkeley, facilitated by the Doktoratskolleg Atoms, Light, and Molecules at Innsbruck.Govind Unnikrishnan, BS, MSDissertation University of Innsbruck 202
Cooling, transport and mixing of ultracold K and Cs
No full textSeit den frühen 1980er Jahren gibt es Vorschläge, große quantenmechanische Systeme zu untersuchen, die für klassische Computer unzugänglich sind, indem sie direkt über ein anderes gut kontrolliertes Quantensystem simuliert werden. Das Aufkommen von Quantengasexperimenten, die auf bahnbrechenden Fortschritten bei der Laserkühlung und dem Einfangen von Atomen aufbauen, beispielhaft dargestellt durch die erste Realisierung eines quantenentarteten Gases im Jahr 1995, hat danach zu einem ganzen Spektrum experimenteller Bemühungen geführt, um hochgradig kontrollierbare Quantensysteme zu realisieren, die zur Durchführung von Quantensimulationen verwendet werden können. Unter den verschiedenen möglichen Plattformen sind polare Bialkali-Moleküle besonders interessant, da sie über abstimmbare, langreichweitige Dipol-Dipol-Wechselwirkungen interagieren. In Kombination mit kürzlich entwickelten Werkzeugen, die eine ortsaufgelöste Abbildung und Adressierung von gittergebundenen Atomen ermöglichen, stellt ein solches System ein vielseitiges Werkzeug zur Untersuchung verschiedener Quantenphänomene bereit. Diese Dissertation konzentriert sich auf die Realisierung mehrerer wichtiger Schritte zur Realisierung eines solchen Quanten-Toolkits unter Verwendung von K- und Cs-Atomen.
Die hochauflösende Abbildung von Atomen, die in einem Gitter gefangen sind, benutzt das Prinzip der Laserkühlung, um zu verhindern, dass die Atome zwischen Gitterstellen tunneln, während das gestreute Licht aufgesammelt wird. Die Auflösung eines solchen Abbildungssystems ist direkt proportional zur Wellenlänge des für die Laserkühlung verwendeten Lichts. In diesem Zusammenhang demonstrieren wir eine Sub-Doppler-Laserkühlung von 39 K unter Verwendung einer entarteten Raman-Seitenbandkühlung über den 4S1/2 5P1/2-Übergang bei 404,8 nm. Im Gegensatz zu den Standard-Laserkühltechniken, die auf den D2- und D1-Übergängen beruhen, wird hier ein hochangeregtes Niveau in den Kühlzyklus integriert.
Die hochauflösende Abbildung kalter Atome erfordert einen guten optischen Zugang. Es liegt daher nahe, den Ort der Erzeugung des Quantengases und die eigentliche Experimentierkammer räumlich zu trennen. Allerdings braucht es dann einen Transport der ultrakalten Atome. Wir stellen mehrere Ansätze und die damit verbundenen Herausforderungen bei der Entwicklung eines geeigneten Transportsystems für unser Experiment vor und schließen mit der Entwicklung eines neuen, auf Moiré-Linsen basierenden, kompakten und robusten Aufbaus, um ultrakalte Atome optisch über große Entfernungen zu transportieren.
Eine Beschreibung der Weiterentwicklung eines parallelen Mischschemas zur Herstellung ultrakalter K-Cs-Mischungen, das den experimentellen Ablauf und Aufwand deutlich vereinfachen soll, wird nachfolgend diskutiert. Zusätzlich wird die Entwicklung einer neuen Experimentierkammer beschrieben. Eine neue solche Kammer ist erforderlich geworden, da in der bestehenden die Vakuumqualität nicht ausreicht. Gleichzeitig gelingt es damit, die Anforderungen an optischem Zugang und Kontrolle des elektrischen Feldes optimal zu erfüllen.
Abschließend wird eine Zusammenfassung der Arbeiten zur Untersuchung der Bandstruktur des Kagome-Gitters präsentiert. Diese Arbeit wurde während eines Forschungsaufenthalts an der University of California, Berkeley, durchgeführt, der durch das Doktoratskolleg "Atoms, Light, and Molecules" in Innsbruck ermöglicht wurde.Proposals to study large quantum mechanical systems that are intractable to classical computers by directly simulating them via another well controlled quantum system have existed since the early 1980s. The emergence of quantum gas experiments building upon pioneering advances in laser cooling and trapping of atoms, exemplified by the first realization of a quantum degenerate gas in 1995, has thereafter given rise to an entire spectrum of experimental efforts to realize highly controllable quantum systems that can be used to carry out quantum simulations. Among the various possible platforms, bialkali polar molecules are especially interesting since they interact via tuneable, long-range dipole-dipole interactions. Combined with more recently developed tools that allow imaging and addressing of lattice bound atoms in a site resolved manner, such a system provides a versatile toolkit to study various quantum phenomena. This thesis is focused on the realization of several important steps towards the realization of such a quantum toolkit using K and Cs atoms.
High resolution imaging of atoms trapped within a lattice relies on laser cooling to prevent the atoms from tunneling between lattices sites, and collecting the light scattered during this process. The resolution of such an imaging system is directly proportional to the wavelength of the light used for laser cooling. In this context, we demonstrate sub-Doppler laser cooling of 39K using degenerate Raman sideband cooling via the 4S1/2 5P1/2 transition at 404.8 nm in contrast to standard laser cooling techniques which rely on the D2 and D1 transitions, where largely closed transition cycles are available.
High resolution imaging of cold atoms require large optical access, which is often met by transporting atoms into a dedicated vacuum chamber containing in-vacuum optics. We present several approaches and the associated challenges in developing a suitable transport system for our experiment, concluding with the development of a new, moiré lens based, compact and robust setup to optically transport ultracold atoms over long distances.
A description of the ongoing development of a parallel mixing scheme for producing ultracold KCs mixtures, which is designed to significantly simplify the experimental sequence and complexity, is provided in Chapter 5. In addition, in view of the compromised vacuum quality in the glass cell meant for high resolution imaging and breakthrough developments in the field that allow robust control over polar molecules by utilizing electric fields generated using specialized infrastructure, a new experimental chamber is being built. We present the design considerations of the most important aspects of the new setup in Chapter 6.
Finally, a summary of the work done on studying the band structure of the Kagome lattice is presented. This work was carried out during a research stay at the University of California, Berkeley, facilitated by the Doktoratskolleg Atoms, Light, and Molecules at Innsbruck.Govind Unnikrishnan, BS, MSDissertation University of Innsbruck 202
Impact of high-fat diet and antioxidant supplement on mitochondrial functions and gene transcripts in rat muscle.
No full textHigh-fat diets are reported to increase oxidative stress in a variety of tissues, whereas antioxidant supplementation prevents many diseases attributed to high-fat diet. Rodent skeletal muscle mitochondrial DNA has been shown to be a potential site of oxidative damage. We hypothesized that the effects of a high-fat diet on skeletal muscle DNA functions would be attenuated or partially reversed by antioxidant supplementation. Gene expression profiling and measurement of mitochondrial ATP production capacity were performed in skeletal muscle from male rats after feeding one of three diets (control, high-fat diet with or without antioxidants) for 36 wk. The high-fat diet altered transcript levels of 18 genes of 800 surveyed compared with the control-fed rats. Alterations included reduced expression of genes involved in free-radical scavenging and tissue development and increased expression of stress response and signal transduction genes. The magnitude of these alterations due to high-fat diet was reduced by antioxidant supplementation. Real-time PCR measurements confirmed the changes in transcript levels of cytochrome c oxidase subunit III and superoxide dismutase-1 and -2 noted by microarray approach. Mitochondrial ATP production was unaltered by dietary changes or antioxidant supplementation. It is concluded that the high-fat diet increases the transcription of genes involved in stress response but reduces those of free-radical scavenger enzymes, resulting in reduced DNA repair/metabolism (increased DNA damage). Antioxidants partially prevent these changes. Mitochondrial functions in skeletal muscle remain unaltered by the dietary intervention due to many adaptive changes in gene transcription
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