1,213 research outputs found
Lifetimes of atoms trapped in an optical lattice in proximity of a surface
We study the lifetime of an atom trapped in an optical vertical lattice in
proximity of a massive surface using a complex scaling approach. We analyze how
the presence of the surface modifies the known lifetimes of Wannier-Stark
states associated to Landau-Zener tunnelling. We also investigate how the
existence of a hypothetical short-distance deviation from Newton's
gravitational law could affect these lifetimes. Our study is relevant in order
to discuss the feasibility of any atomic- interferometry experiment performed
near a surface. Finally, the difficulties encountered in applying the
complex-scaling approach to the atom-surface Casimir-Polder interaction are
addressed.Comment: 10 pages, 8 figure
"il senso del vedere giudichera" Il ruolo del disegno nella teoria e nella pratica dell'architettura religiosa di Francesco di Giorgio Martini
Lo studio analizza i trattati architettonici di Francesco di Giorgio Martini, figura polivalente di architetto, ingegnere e artista, di origine senese, vissuto nel XV secolo. Dopo una rassegna della fortuna di Francesco negli studi moderni ed una contestualizzazione dellâautore nella sua temperie culturale in rapporto ai suoi predecessori e contemporanei, si prendono in considerazione i manoscritti rimanenti di alcune sue opere, che, rivisti autotticamente, vengono analizzati sotto un duplice aspetto. Da una parte lâinterazione di testo e immagine (i numerosi disegni presenti) per mostrarne la novitĂ non solo a livello visivo, ma anche le profonde conseguenze che questa nuova forma ha sui contenuti e sulle strategie argomentative. Dallâaltra si esaminano con particolare attenzione le sezioni su chiese, templi e colonne (architettura religiosa), sia per il loro valore intrinseco sia per trarne notizie utili allâattribuzione di opere incerte alla mano di Francesco
Laser controlled tunneling in a vertical optical lattice
Raman laser pulses are used to induce coherent tunnelling between
neighbouring sites of a vertical 1D optical lattice. Such tunneling occurs when
the detuning of a probe laser from the atomic transition frequency matches
multiples of the Bloch frequency, allowing for a spectroscopic control of the
coupling between Wannier Stark (WS) states. In particular, we prepare coherent
superpositions of WS states of adjacent sites, and investigate the coherence
time of these superpositions by realizing a spatial interferometer. This scheme
provides a powerful tool for coherent manipulation of external degrees of
freedom of cold atoms, which is a key issue for quantum information processing
ApoB-Specific CD4+ T Cells in Mouse and Human Atherosclerosis
Atherosclerosis is a chronic inflammatory condition of the arterial wall that leads to the formation of vesselâoccluding plaques within the subintimal space of middleâsized and larger arter-ies. While traditionally understood as a myeloidâdriven lipidâstorage disease, growing evidence suggests that the accumulation of lowâdensity lipoprotein cholesterol (LDLâC) ignites an autoimmune response with CD4+ Tâhelper (TH) cells that recognize selfâpeptides from Apolipoprotein B (ApoB), the core protein of LDLâC. These autoreactive CD4+ T cells home to the atherosclerotic plaque, clonally expand, instruct other cells in the plaque, and induce clinical plaque instability. Recent developments in detecting antigenâspecific cells at the single cell level have demonstrated that ApoBâreactive CD4+ T cells exist in humans and mice. Their phenotypes and functions deviate from classical immunological concepts of distinct and terminally differentiated TH immunity. In-stead, ApoBâspecific CD4+ T cells have a highly plastic phenotype, can acquire several, partially opposing and mixed transcriptional programs simultaneously, and transit from one TH subset into another over time. In this review, we highlight adaptive immune mechanisms in atherosclerosis with a focus on CD4+ T cells, introduce novel technologies to detect ApoBâspecific CD4+ T cells at the single cell level, and discuss the potential impact of ApoBâdriven autoimmunity in atheroscle-rosis.Fil: Marchini, Timoteo Oscar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de BioquĂmica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de BioquĂmica y Medicina Molecular; Argentina. Albert Ludwigs University of Freiburg; AlemaniaFil: Hansen, Sophie. Albert Ludwigs University of Freiburg; AlemaniaFil: Wolf, Dennis. Albert Ludwigs University of Freiburg; Alemani
MORG1âA Negative Modulator of Renal Lipid Metabolism in Murine Diabetes
Renal fatty acid (FA) metabolism is severely altered in type 1 and 2 diabetes mellitus (T1DM and T2DM). Increasing evidence suggests that altered lipid metabolism is linked to tubulointerstitial fibrosis (TIF). Our previous work has demonstrated that mice with reduced MORG1 expression, a scaffold protein in HIF and ERK signaling, are protected against TIF in the db/db mouse model. Renal TGF-Ă1 expression and EMT-like changes were reduced in mice with single-allele deficiency of MORG1. Given the well-known role of HIF and ERK signaling in metabolic regulation, here we examined whether protection was also associated with a restoration of lipid metabolism. Despite similar features of TIF in T1DM and T2DM, diabetes-associated changes in renal lipid metabolism differ between both diseases. We found that de novo synthesis of FA/cholesterol and ÎČ-oxidation were more strongly disrupted in T1DM, whereas pathological fat uptake into tubular cells mediates lipotoxicity in T2DM. Thus, diminished MORG1 expression exerts renoprotection in the diabetic nephropathy by modulating important factors of TIF and lipid dysregulation to a variable extent in T1DM and T2DM. Prospectively, targeting MORG1 appears to be a promising strategy to reduce lipid metabolic alterations in diabetic nephropathy
Socio-cultural and behavioural factors constraining latrine adoption in rural coastal Odisha: an exploratory qualitative study.
BACKGROUND: Open defecation is widely practiced in India. To improve sanitation and promote better health, the Government of India (GOI) has instituted large scale sanitation programmes supporting construction of public and institutional toilets and extending financial subsidies for poor families in rural areas for building individual household latrines. Nevertheless, many household latrines in rural India, built with government subsidies and the facilitation and support of non-government organizations (NGO), remain unused. Literature on social, cultural and behavioural aspects that constrain latrine adoption and use in rural India is limited. This paper examines defecation patterns of different groups of people in rural areas of Odisha state in India to identify causes and determinants of latrine non-use, with a special focus on government-subsidized latrine owners, and shortcomings in household sanitation infrastructure built with government subsidies. METHODS: An exploratory study using qualitative methods was conducted in rural communities in Odisha state. Methods used were focus group discussions (FGDs), and observations of latrines and interviews with their owners. FGDs were held with frontline NGO sanitation program staff, and with community members, separately by caste, gender, latrine type, and age group. Data were analysed using a thematic framework and approach. RESULTS: Government subsidized latrines were mostly found unfinished. Many counted as complete per government standards for disbursement of financial subsidies to contracted NGOs were not accepted by their owners and termed as 'incomplete'. These latrines lacked a roof, door, adequate walls and any provision for water supply in or near the cabin, whereas rural people had elaborate processes of cleansing with water post defecation, making presence of a nearby water source important. Habits, socialising, sanitation rituals and daily routines varying with caste, gender, marital status, age and lifestyle, also hindered the adoption of latrines. Interest in constructing latrines was observed among male heads for their female members especially a newlywed daughter-in-law, reflecting concerns for their privacy, security, and convenience. This paper elaborates on these different factors. CONCLUSIONS: Findings show that providing infrastructure does not ensure use when there are significant and culturally engrained behavioural barriers to using latrines. Future sanitation programmes in rural India need to focus on understanding and addressing these behavioural barriers
Atomic states in optical traps near a planar surface
In this work we discuss the atomic states in a vertical optical lattice in
proximity of a surface. We study the modifications to the ordinary
Wannier-Stark states in presence of a surface and we characterize the energy
shifts produced by the Casimir-Polder interaction between atom and mirror. In
this context, we introduce an effective model describing the finite size of the
atom in order to regularize the energy corrections. In addition, the
modifications to the energy levels due to a hypothetical non-Newtonian
gravitational potential as well as their experimental observability are
investigated.Comment: 12 pages, 8 figure
En kvalitativ studie for hvordan ledere lĂŠrer ledelse
Det er lite som er sÄ lett Ä omtale med store ord, og samtidig sÄ vanskelig Ä fÄ til i praksis som
ledelse. Ettersom det settes stadig hĂžyere krav til lederrollen og lederens utĂžvelse av ledelse
er dette noe som vi mener er viktig Ä forstÄ bedre. Ledelse er komplekst, noe som speiles av
de utallige teorier og perspektiver som finnes der ute. Ledelseslitteraturen handler i stor grad
om hvordan ledelse kan forstÄs, hvordan ledere bÞr vÊre og hva som kjennetegner gode
ledere. Hvordan ledere lĂŠrer seg ledelse er i stĂžrre grad ukjent og ubeskrevet, og det er dette
vi forsĂžker Ă„ belyse i denne oppgaven. I denne studien har vi benyttet et kvalitativt
forskningsdesign med dybdeintervju som datainnsamlingsmetode. Vi har utfĂžrt 12 kvalitative
dybdeintervjuer, og informantene bestÄr av mellomledere fra forskjellige organisasjoner og
ulike bransjer. Intervjuene ble transkribert fortlĂžpende, og deretter kategorisert og analysert.
Vi finner at ledelse lĂŠres gjennom Ă„ praktisere, og kan ikke alene lĂŠres gjennom formell
lÊring som lederutdanning og kurs. Eksplisitt kunnskap og teorier om ledelse fÄr fÞrst verdi
nÄr den benyttes i praksis. I motsetning til hva man gjerne tror, finner vi at lederens viktigste
lĂŠringsarenaer er de uformelle. Den viktigste lĂŠringen skjer gjennom Ă„ lede i den konteksten
lederen er i hverdagen, hvor sosial interaksjon med medarbeidere og andre ledere er sentralt.
Gjennom Ă„ praktisere, observere og kommunisere sammen med andre vil lederen tilegne seg
taus kunnskap som er relevant for sin ledelsespraksis. Videre identifiserer vi praksisfelleskap
som en annen viktig lĂŠringsarena. Gjennom at det forhandles frem kunnskap i
praksisfellesskapet og formidles videre til lederen utenfor praksisfellesskapet, vil det fremme
lĂŠring og utvikling hos lederen. Ved Ă„ tilrettelegge for formelle praksisfellesskap kan lederen
fremme kunnskapsdelingen mellom ulike nivÄer og fagomrÄder i organisasjonen. Videre vil
kunnskapsdeling med medarbeidere og andre ledere gi lederen nye perspektiver samt at en vil
tilegne seg ny kunnskap. Til slutt finner vi at refleksjon danner grunnlag for lĂŠring og
handling, og er avgjĂžrende for Ă„ kunne lĂŠre av det lederen gjĂžr i sin ledelsespraksis og for at
det skal bli kontinuerlig utviklende. En direkte konsekvens av vÄre funn tilsier at man bÞr
vÊre forsiktig med Ä ukritisk se pÄ lederkurs som en magisk formel for Ä kunne bli en god
leder, men at de heller bÞr sees pÄ som verktÞy for Ä lÞse identifiserte mangler eller gi
nÞdvendig faglig pÄfyll
Swiss stained-glass panels: an analytical study
The history and iconography of Swiss stained glass dating between the 16th and 18th centuries are well studied. However, the chemical and morphological characteristics of the glass and glass paints, particularly the nature of the raw materials, the provenance of the glass, and the technology used to produce it are less well understood. In this paper, we studied two sets of samples from stained-glass panels attributed to Switzerland, which date from the 16th to 17th centuries: the first set comes from Pena National Palace collection, the second from Vitrocentre Romont. The aims were to identify the materials used in the production of the glass, to find out more about their production origin and to characterize the glass paints. Both glass and the glass paints were analysed by particle-induced X-ray emission; the paints were additionally analysed by scanning electron microscopyâelectron-dispersive X-ray spectroscopy (SEM-EDS). The results show that the glass from both sets was probably produced in the same region and that wood ash was used as a fluxing agent. Different recipes have been used to make the blue enamels. However, the cobalt ore used as a coloring agent in all of the blue enamels came from the mining district in Schneeberg, Germany
Validation of a German Version of the Stress Overload Scale and Comparison of Different Time Frames in the Instructions
Abstract: Introduction: The Stress Overload Scale (SOS; Amirkhan, 2012 , 2018 ) was introduced as a two-factorial self-report measure of stress to overcome limitations of other scales. Methods: We developed a German translation of the SOS and validated it in addition to a short version and an extra-short version. Furthermore, we tested whether manipulating the time frame introduced as retention interval in the instructions affected its psychometric properties. Results: Using two independent age-heterogeneous convenience samples ( Ntotal = 1,239), we found good psychometric properties for a modified German short version of the SOS-S (SOS-S-G) and a new extra-short version (SOS-XS-G), but not for the German long version of the SOS. Moreover, manipulating the time frame of the SOS did not affect its psychometric quality. Discussion The SOS enriches the repertoire of self-report measures of stress as it captures the nonpathological core facets of stress in line with theoretical stress conceptualizations
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