967 resultados para displacement spectra
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We present experimental results on inclusive spectra and mean multiplicities of negatively charged pions produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158GeV/c (√s = 6.3, 7.7,8.8, 12.3 and 17.3GeV, respectively). The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN super proton synchrotron. Two-dimensional spectra are determined in terms of rapidity and transverse momentum. Their properties such as the width of rapidity distributions and the inverse slope parameter of transverse mass spectra are extracted and their collision energy dependences are presented. The results on inelastic p+p interactions are compared with the corresponding data on central Pb+Pb collisions measured by the NA49 experiment at the CERNSPS. The results presented in this paper are part of the NA61/SHINE ion program devoted to the study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. They are required for interpretation of results on nucleus–nucleus and proton–nucleus collisions.
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Over the last two decades, there has been a radical shift in anthropology from stable, rooted and mappable identities to fluid, transitory and migratory forms of belonging. Displacement has become the new trope through which anthropologists have come to look at the world. As a result, place has received an ambiguous position. Focusing on the life experiences of one Somali refugee woman living in Melbourne and her engagement with place, this article questions the current emphasis on space and boundlessness in anthropological discourses on displacement. It argues that rather than developing theoretical concepts that bypass people's experiences, the zooming in on individuals' lifeworlds allows for a close look at the particularity and everydayness of being-in-place. It shows the need for a more complex and nuanced view of displacement – one that values people's lived experiences and one that takes the placement in displacement more seriously.
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Lipid resonances from mobile lipids can be observed by (1)H NMR spectroscopy in multiple tissues and have also been associated with malignancy. In order to use lipid resonances as a marker for disease, a reference standard from a healthy tissue has to be established taking the influence of variable factors like the spinning rate into account. The purpose of our study was to investigate the effect of spinning rate variation on the HR-MAS pattern of lipid resonances in non-neoplastic brain biopsies from different regions and visualize polar and non-polar lipids by fluorescence microscopy using Nile Red staining. (1)H HR-MAS NMR spectroscopy demonstrated higher lipid peak intensities in normal sheep brain pure white matter biopsies compared to mixed white and gray matter biopsies and pure gray matter biopsies. High spinning rates increased the visibility particularly of the methyl resonances at 1.3 and the methylene resonance at 0.89ppm in white matter biopsies stronger compared to thalamus and brainstem biopsies, and gray matter biopsies. The absence of lipid droplets and presence of a large number of myelin sheaths observed in white matter by Nile Red fluorescence microscopy suggest that the observed lipid resonances originate from the macromolecular pool of lipid protons of the myelin sheath's plasma membranes. When using lipid contents as a marker for disease, the variable behavior of lipid resonances in different neuroanatomical regions of the brain and at variable spinning rates should be considered. The findings may open up interesting possibilities for investigating lipids in myelin sheaths.
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The S0 ↔ S1 spectra of the mild charge-transfer (CT) complexes perylene·tetrachloroethene (P·4ClE) and perylene·(tetrachloroethene)2 (P·(4ClE)2) are investigated by two-color resonant two-photon ionization (2C-R2PI) and dispersed fluorescence spectroscopy in supersonic jets. The S0 → S1 vibrationless transitions of P·4ClE and P·(4ClE)2 are shifted by δν = −451 and −858 cm–1 relative to perylene, translating to excited-state dissociation energy increases of 5.4 and 10.3 kJ/mol, respectively. The red shift is ∼30% larger than that of perylene·trans-1,2-dichloroethene; therefore, the increase in chlorination increases the excited-state stabilization and CT character of the interaction, but the electronic excitation remains largely confined to the perylene moiety. The 2C-R2PI and fluorescence spectra of P·4ClE exhibit strong progressions in the perylene intramolecular twist (1au) vibration (42 cm–1 in S0 and 55 cm–1 in S1), signaling that perylene deforms along its twist coordinate upon electronic excitation. The intermolecular stretching (Tz) and internal rotation (Rc) vibrations are weak; therefore, the P·4ClE intermolecular potential energy surface (IPES) changes little during the S0 ↔ S1 transition. The minimum-energy structures and inter- and intramolecular vibrational frequencies of P·4ClE and P·(4ClE)2 are calculated with the dispersion-corrected density functional theory (DFT) methods B97-D3, ωB97X-D, M06, and M06-2X and the spin-consistent-scaled (SCS) variant of the approximate second-order coupled-cluster method, SCS-CC2. All methods predict the global minima to be π-stacked centered coplanar structures with the long axis of tetrachloroethene rotated by τ ≈ 60° relative to the perylene long axis. The calculated binding energies are in the range of −D0 = 28–35 kJ/mol. A second minimum is predicted with τ ≈ 25°, with ∼1 kJ/mol smaller binding energy. Although both monomers are achiral, both the P·4ClE and P·(4ClE)2 complexes are chiral. The best agreement for adiabatic excitation energies and vibrational frequencies is observed for the ωB97X-D and M06-2X DFT methods.
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The surfaces of many objects in the Solar System comprise substantial quantities of water ice sometimes mixed with minerals and/or organic molecules. The sublimation of the ice changes the structural and optical properties of these objects. We present laboratory data on the evolution of the structure and the visible and near-infrared spectral reflectance of icy surface analogues of cometary ices, made of water ice, complex organic matter (tholins) and silicates, as they undergo sublimation under low temperature (<-70°C) and pressure (10-⁵mbar) conditions inside the SCITEAS simulation chamber. As the water ice sublimated, we observed in situ the formation of a porous sublimation lag deposit, or sublimation mantle, at the top of the ice. This mantle is a network of filaments made of the non-volatile particles. Organics or phyllosilicates grains, able to interact via stronger inter-particulate forces than olivine grains, can form a foam-like structure having internal cohesiveness, holding olivine grains together. As this mantle builds-up, the band depths of the sub-surface water ice are attenuated until complete extinction under only few millimeters of mantle. Optically thick sublimation mantles are mainly featureless in the near infrared. The absorption bands of the minerals present in the mantle are weak, or even totally absent if minerals are mixed with organics which largely dominate the VIS–NIR reflectance spectrum. During sublimation, ejections of large fragments of mantle, triggered by the gas flow, expose ice particles to the surface. The contrast of brightness between mantled and ice-exposed areas depends on the wavelength range and the dust/ice ratio considered. We describe how the chemical nature of the non-volatiles, the size of their particles, the way they are mixed with the ice and the dust/ice mass ratio influence the texture, activity and spectro-photometric properties of the sublimation mantles. These data provide useful references for interpreting remote-sensing observations of comets and also icy satellites or trans-neptunian objects.
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Throughout the last decades, narrative approaches have become quintessential tools for understanding crisis and displacement. While a focus on individual stories allows for a deep look into the particularity of being-displaced, it simultaneously runs the risk of romanticising the outcome (the life story) of what is indeed the product of a rather complex process (the telling of the life story). In this paper I will discuss a change of perspectives: Rather than laying the focus on life stories as texts, I will suggest to shift the attention towards the existential dynamics of storytelling. By zooming in on my longstanding collaboration with a Somali woman in Melbourne, Australia, I will map out the interplay of telling and being that marked this process. Focusing on one particular storytelling moment, I will suggest the importance of appreciating the intersubjective force of storytelling. Rather than melting the set of stories into a coherent “life story”, I will look at the storytelling moment in its lived messiness. In doing so, I will sketch out its potential to shed light both on the teller’s hopes, imaginations and ambitions, and on the reality of being part of a wider world that often contradicts and shatters these hopes.
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INTRODUCTION Investigations of the dynamic function of female pelvic floor muscles (PFM) help us to understand the pathophysiology of stress urinary incontinence (SUI). Displacement measurements of PFM give insight into muscle activation and thus help to improve rehabilitation strategies. This systematic review (PROSPERO 2013: CRD42013006409) was performed to summarise the current evidence for PFM displacement during voluntary and involuntary activation in continent and incontinent women. METHODS MEDLINE, EMBASE, Cochrane and SPORTDiscus databases were searched using selected terminology reflecting the PICO approach. Screening of Google Scholar and congress abstracts added to further information. Original articles investigating PFM displacement were included if they reported on at least one of the aims of the review, e.g., method, test position, test activity, direction and quantification of displacement, as well as the comparison between continent and incontinent women. Titles and abstracts were screened by two reviewers. The papers included were reviewed by two individuals to ascertain whether they fulfilled the inclusion criteria and data were extracted on outcome parameters. RESULTS Forty-two predominantly observational studies fulfilled the inclusion criteria. A variety of measurement methods and calculations of displacement was presented. The sample was heterogeneous concerning age, parity and continence status. Test positions and test activities varied among the studies. CONCLUSIONS The findings summarise the present knowledge of PFM displacement, but still lack deeper comprehension of the SUI pathomechanism of involuntary, reflexive activation during functional activities. We therefore propose that future investigations focus on PFM dynamics during fast and stressful impact tasks.
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Every x-ray attenuation curve inherently contains all the information necessary to extract the complete energy spectrum of a beam. To date, attempts to obtain accurate spectral information from attenuation data have been inadequate.^ This investigation presents a mathematical pair model, grounded in physical reality by the Laplace Transformation, to describe the attenuation of a photon beam and the corresponding bremsstrahlung spectral distribution. In addition the Laplace model has been mathematically extended to include characteristic radiation in a physically meaningful way. A method to determine the fraction of characteristic radiation in any diagnostic x-ray beam was introduced for use with the extended model.^ This work has examined the reconstructive capability of the Laplace pair model for a photon beam range of from 50 kVp to 25 MV, using both theoretical and experimental methods.^ In the diagnostic region, excellent agreement between a wide variety of experimental spectra and those reconstructed with the Laplace model was obtained when the atomic composition of the attenuators was accurately known. The model successfully reproduced a 2 MV spectrum but demonstrated difficulty in accurately reconstructing orthovoltage and 6 MV spectra. The 25 MV spectrum was successfully reconstructed although poor agreement with the spectrum obtained by Levy was found.^ The analysis of errors, performed with diagnostic energy data, demonstrated the relative insensitivity of the model to typical experimental errors and confirmed that the model can be successfully used to theoretically derive accurate spectral information from experimental attenuation data. ^
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Diethylstilbestrol (DES) is a known human carcinogen and teratogen whose mechanism of action remains undetermined. As essentially diploid Chinese hamster cell line (Don) was used to test diethylstilbestrol (DES), dienestrol, hexestrol and the naturally occurring estrogens, estradiol and estriol for their ability to cause metaphase arrest and to induce aneuploidy. These compounds arrest mitosis within a narrow range of high concentrations and induce aneuploidy in recovering cell populations. DES was the most effective arrestant on a comparative molar basis. Estradiol and estriol were less potent as arrestants but were effective inducers of aneuploidy. Aneuploidy was induced in a non-random manner. The smallest chromosomes were most frequently recorded in aneuploid cells. Using anti-tubulin antibody and indirect immunofluorescence, it was found that DES inhibits bi-polar spindle assembly and disrupts the cytoplasmic microtubule complex (CMTC). Estradiol arrests mitosis in a manner that allows spindle assembly. Estradiol has no apparent effect on the CMTC. The naturally occurring estrogens caused chromosome displacement during mitotic arrest. Electron microscopy confirmed that the displaced chromosomes appeared at the polar regions of arrested cells. The arresting effect of estradiol, and to some extent DES, was reduced by the addition of dibutyryl cyclic adenosine monophosphate (db-cAMP). Aneuploidy induction by DES and similar compounds may be related to their carcinogenic and/or teratogenic potential. ^