298 resultados para Lyman
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We employ a numerical model of cusp ion precipitation and proton aurora emission to fit variations of the peak Doppler-shifted Lyman-a intensity observed on 26 November 2000 by the SI-12 channel of the FUV instrument on the IMAGE satellite. The major features of this event appeared in response to two brief swings of the interplanetary magnetic field (IMF) toward a southward orientation. We reproduce the observed spatial distributions of this emission on newly opened field lines by combining the proton emission model with a model of the response of ionospheric convection. The simulations are based on the observed variations of the solar wind proton temperature and concentration and the interplanetary magnetic field clock angle. They also allow for the efficiency, sampling rate, integration time and spatial resolution of the FUV instrument. The good match (correlation coefficient 0.91, significant at the 98% level) between observed and modeled variations confirms the time constant (about 4 min) for the rise and decay of the proton emissions predicted by the model for southward IMF conditions. The implications for the detection of pulsed magnetopause reconnection using proton aurora are discussed for a range of interplanetary conditions.
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We study a brightening of the Lyman-alpha emission in the cusp which occurred in response to a short-lived southward turning of the interplanetary magnetic field (IMF) during a period of strongly enhanced solar wind plasma concentration. The cusp proton emission is detected using the SI-12 channel of the FUV imager on the IMAGE spacecraft. Analysis of the IMF observations recorded by the ACE and Wind spacecraft reveals that the assumption of a constant propagation lag from the upstream spacecraft to the Earth is not adequate for these high time-resolution studies. The variations of the southward IMF component observed by ACE and Wind allow for the calculation of the ACE-to-Earth lag as a function of time. Application of the derived propagation delays reveals that the intensity of the cusp emission varied systematically with the IMF clock angle, the relationship being particularly striking when the intensity is normalised to allow for the variation in the upstream solar wind proton concentration. The latitude of the cusp migrated equatorward while the lagged IMF pointed southward, confirming the lag calculation and indicating ongoing magnetopause reconnection. Dayside convection, as monitored by the SuperDARN network of radars, responded rapidly to the IMF changes but lagged behind the cusp proton emission response: this is shown to be as predicted by the model of flow excitation by Cowley and Lockwood (1992). We use the numerical cusp ion precipitation model of Lockwood and Davis (1996), along with modelled Lyman-_ emission efficiency and the SI-12 instrument response, to investigate the effect of the sheath field clock angle on the acceleration of ions on crossing the dayside magnetopause. This modelling reveals that the emission commences on each reconnected field line 2–2.5min after it is opened and peaks 3–5 min after it is opened. We discuss how comparison of the Lyman-alpha intensities with oxygen emissions observed simultaneously by the SI-13 channel of the FUV instrument offers an opportunity to test whether or not the clock angle dependence is consistent with the “component” or the “anti-parallel” reconnection hypothesis.
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The classification of galaxies as star forming or active is generally done in the ([O III]/H beta, [N II]/H alpha) plane. The Sloan Digital Sky Survey (SDSS) has revealed that, in this plane, the distribution of galaxies looks like the two wings of a seagull. Galaxies in the right wing are referred to as Seyfert/LINERs, leading to the idea that non-stellar activity in galaxies is a very common phenomenon. Here, we argue that a large fraction of the systems in the right wing could actually be galaxies which stopped forming stars. The ionization in these `retired` galaxies would be produced by hot post-asymptotic giant branch stars and white dwarfs. Our argumentation is based on a stellar population analysis of the galaxies via our STARLIGHT code and on photoionization models using the Lyman continuum radiation predicted for this population. The proportion of LINER galaxies that can be explained in such a way is, however, uncertain. We further show how observational selection effects account for the shape of the right wing. Our study suggests that nuclear activity may not be as common as thought. If retired galaxies do explain a large part of the seagull`s right wing, some of the work concerning nuclear activity in galaxies, as inferred from SDSS data, will have to be revised.
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This work presents the first integral field spectroscopy of the Homunculus nebula around eta Carinae in the near-infrared spectral region (J band). We confirmed the presence of a hole on the polar region of each lobe, as indicated by previous near-IR long-slit spectra and mid-IR images. The holes can be described as a cylinder of height (i.e. the thickness of the lobe) and diameter of 6.5 and 6.0 x 10(16) cm, respectively. We also mapped the blue-shifted component of He I lambda 10830 seen towards the NW lobe. Contrary to previous works, we suggested that this blue-shifted component is not related to the Paddle but it is indeed in the equatorial disc. We confirmed the claim of N. Smith and showed that the spatial extent of the Little Homunculus matches remarkably well the radio continuum emission at 3 cm, indicating that the Little Homunculus can be regarded as a small H II region. Therefore, we used the optically thin 1.3 mm radio flux to derive a lower limit for the number of Lyman-continuum photons of the central source in eta Car. In the context of a binary system, and assuming that the ionizing flux comes entirely from the hot companion star, the lower limit for its spectral type and luminosity class ranges from O5.5 III to O7 I. Moreover, we showed that the radio peak at 1.7 arcsec NW from the central star is in the same line-of-sight of the `Sr-filament` but they are obviously spatially separated, while the blue-shifted component of He I lambda 10830 may be related to the radio peak and can be explained by the ultraviolet radiation from the companion star.
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We show that the significantly different effective temperatures (T(eff)) achieved by the luminous blue variable AG Carinae during the consecutive visual minima of 1985-1990 (T(eff) similar or equal to 22,800 K) and 2000-2001 (T(eff) similar or equal to 17,000 K) place the star on different sides of the bistability limit, which occurs in line-driven stellar winds around T(eff) similar to 21,000 K. Decisive evidence is provided by huge changes in the optical depth of the Lyman continuum in the inner wind as T(eff) changes during the S Dor cycle. These changes cause different Fe ionization structures in the inner wind. The bistability mechanism is also related to the different wind parameters during visual minima: the wind terminal velocity was 2-3 times higher and the mass-loss rate roughly two times smaller in 1985-1990 than in 2000-2003. We obtain a projected rotational velocity of 220 +/- 50 km s(-1) during 1985-1990 which, combined with the high luminosity (L(star) = 1.5 x 10(6) L(circle dot)), puts AG Car extremely close to the Eddington limit modified by rotation (Omega Gamma limit): for an inclination angle of 90 degrees, Gamma(Omega) greater than or similar to 1.0 for M(circle dot) less than or similar to 60. Based on evolutionary models and mass budget, we obtain an initial mass of similar to 100 M(circle dot) and a current mass of similar to 60-70 M(circle dot) for AG Car. Therefore, AG Car is close to, if not at, the Omega Gamma limit during visual minimum. Assuming M = 70 M(circle dot), we find that Gamma(Omega) decreases from 0.93 to 0.72 as AG Car expands toward visual maximum, suggesting that the star is not above the Eddington limit during maximum phases.
Resumo:
Syftet med denna litteraturstudie är att beskriva hur standardvårdplaner, kan vara ett instrument som förbättrar omvårdnadskvalitén för patienter och närstående i sen palliativ fas.Artiklarna söktes via Högskolan Dalarnas bibliotek och Falu lasaretts bibliotek. Artiklar från andra referenser ingår också i studien. Totalt har 17 artiklar använts i resultatredovisningen. Resultatet visar att efter införandet av standardvårdplan förbättrades följande områden; symtomkontrollen, anhörigstöd efter dödsfallet, kommunikation, omvårdnadens standard och evidens. Fokus lades på att prioritera viktiga omvårdnadsåtgärder och det visar sig att standardvårdplanen Integrated Care Pathway (ICP) är ett användbart pedagogiskt instrument vid kvalitetsförbättringar i palliativvård. Negativa synpunkter som framkom var att standardvårdplaner är ett oflexibelt, pappersorienterat, generaliserande instrument och outvecklat för andra diagnoser än cancer.
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A partir de três conceitos fundamentais para a compreensão da dinâmica das relações familiares: a pseudo-mutualidade, elaborada por Wynne, nos Estados Unidos, o postulado fusional, desenvolvido por Hochmann, na França e a mistificação, por Laing, na Inglaterra, investigou-se a estrutura de relações familiares em um texto teatral brasileiro, atual, "Do Fundo do Lago Escuro", de Domingos de Oliveira. Os três conceitos acima citados, fundamentais para a compreensão da dinâmica das relações familiares dentro de uma perspectiva sistêmica (não-psicanalítica),estão interrelacionados entre si e surgiram apartir de estudos realizados com famílias com um membro esquizofrênico, em três diferentes paises. Buscou-se estabelecer os pontos de contato, as divergências metodológicas, teóricas e ideológicas e os aspectos complementares dos referidos conceitos, bem como verificar sua aplicabilidade a uma estrutura familiar considerada representativa de certa parcela da sociedade brasileira, em determinada ocasião. Concluiu-se pela aplicabilidade dos conceitos, desenvolvidos em três diferentes países, a uma dada estrutura familiar brasileira em um dado momento histórico, e pela aplicabilidade dos conceitos a um grupo familiar que não apresenta, através de qualquer de seus membros, um quadro esquizofrênico manifesto.
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Practical methods for land grading design of a plane surface for rectangular and irregularly shaped fields based on a least squares analysis are presented. The least squares procedure leads to a system of three linear equations with three unknowns for determination of the best-fit plane. The equations can be solved by determinants (Cramer's rule) using a procedure capable of solution by many programmable calculators. The detailed computational process for determining the equation of the plane and a simple method to find the centroid location of an irregular field are also given. An illustrative example and design instructions are included to demonstrate the application of the design procedure.
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We report a study of the stellar content of the near-infrared (NIR) cluster [DBS2003] 157 embedded in the extended H ii region GAL 331.31-00.34, which is associated with the IRAS source 16085-5138. JHK photometry was carried out in order to identify potential ionizing candidates, and the follow-up NIR spectroscopy allowed the spectral classification of some sources, including two O-type stars. A combination of NIR photometry and spectroscopy data was used to obtain the distance of these two stars, with the method of spectroscopic parallax: IRS 298 (O6 V, 3.35 +/- 0.61 kpc) and IRS 339 (O9 V, 3.24 +/- 0.56 kpc). Adopting the average distance of 3.29 +/- 0.58 kpc and comparing the Lyman continuum luminosity of these stars with that required to account for the radio continuum flux of the H ii region, we conclude that these two stars are the ionizing sources of GAL 331.31-00.34. Young stellar objects (YSOs) were searched by using our NIR photometry and mid-infrared (MIR) data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) survey. The analysis of NIR and MIR colourcolour diagrams resulted in 47 YSO candidates. The GLIMPSE counterpart of IRAS 16085-5138, which presents IRAS colour indices compatible with an ultracompact H ii region, has been identified. The analysis of its spectral energy distribution between 2 and m revealed that this source shows a spectral index a= 3.6 between 2 and m, which is typical of a YSO immersed in a protostellar envelope. Lower limits to the bolometric luminosity and the mass of the embedded protostar have been estimated as L= 7.7 x 10(3) L? and M= 10 M?, respectively, which correspond to a B0B1 V zero-age main sequence star.
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New Cosmic Origins Spectrograph (COS) observing modes have extended the Hubble Space Telescope's spectral range to wavelengths between 900-1150 Å. However, the G140L/1280 and the Cycle 19 available G130M central wavelengths (1055 and 1096) that sample below 1150 Å were only available at focus positions which provided low-resolution (R<3,000). For HST Cycle 20, we introduced a new G130M/1222 central wavelength that covers 1065-1365 Å with R>10,000 everywhere, but optimized for 15000 from 1080-1200 Å. This mode places geo-coronal Lyα between the COS FUV detector segments to minimize detector gain sag. Also for Cycle 20, the resolution of the G130M/1055 and 1096 modes will be increased by a factor of 3-4 by optimizing the focus positions for these modes. This will give HST approximately the effective area of FUSE over the FUSE bandpass at 10,000. Here we present the current calibration status of the COS G130M/1055, 1096, and 1222 central wavelength settings at the original and second FUV lifetime positions with an emphasis on observing over the "Lyman UV", or "LUV", 912-1216 Å.
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In dieser Arbeit wird eine kohärente, kontinuierliche Strahlungsquelle im vakuum-ultravioletten (VUV) Spektrum vorgestellt. Sie basiert auf einem Vierwellenmischprozess in Quecksilberdampf mit Fundamentalstrahlen bei 253,7 nm, 407,9 nm und 545,5 nm Wellenlänge. Diese fundamentalen Strahlen werden durch frequenzverdoppelte bzw. frequenzvervierfachte Festkörperlasersysteme bereit gestellt. Durch das Ausnutzen der 6^1S-7^1S Zweiphotonenresonanz und zusätzlich der 6^1S-6^3P Einphotonenresonanz kann der Vierwellenmischprozess deutlich effizienter betrieben werden als zuvor. Eine nahe Einphotonenresonanz verringert die optimale Phasenanpassungstemperatur des Vierwellenmischprozesses, wodurch Druck- und Stoßverbreiterungen des Quecksilbers verkleinert und damit der nichtlineare Prozess effizienter wird. So können Leistungen bis zu 0,3 nW bei 121,56 nm, dem 1S-2P Lyman-alpha Übergang von Wasserstoff, erzeugt werden. Diese Lyman-alpha Quelle soll für die zukünftige Laserkühlung von Antiwasserstoff genutzt werden. rnrnNeben der Generierung von Strahlung bei Lyman-alpha kann, durch Veränderung der dritten Fundamentalwellenlänge, auch Strahlung in der Nähe zu einer Einphotonresonanz im VUV bei dem 6^1S-12^1P Übergang in Quecksilber durch Vierwellenmischen erzeugt werden. Durch diese weitere Einphotonresonanz kann die nichtlineare Suszeptibilität, verantwortlich für das Vierwellenmischen, stark vergrößert werden, ohne Einfluss auf die Phasenanpassung zu haben. Damit lässt sich der Mischprozess um drei Größenordnungen effizienter gestalten und Leistungen von 6 µW im VUV konnten realisiert werden. Dies entspricht einer Leistungsteigerung um einen Faktor 30 im Vergleich zu früheren Quellen. rnrnDarüberhinaus konnte die Zweiphotonenresonanz in Quecksilber ausführlich untersucht werden. Man erhält bei kleinen Rabifrequenzen der Fundamentalstrahlen eine geschwindigkeitsselektive Doppelresonanz, die den gleichen Ursprung wie Dunkelresonanzen in Lambda-Systemen hat. Bei hohen Rabifrequenzen kann die Anregung in das Zweiphotonenniveau so stark werden, dass auf dem 7^1S-6^1P Übergang ein Laserprozess initiiert wird. Dieser Prozess wurde hier zum ersten Mal mit kontinuierlichen Fundamentallasern nachgewiesen. Es wird gezeigt, dass der zusätzliche Laserprozess das Vierwellenmischen nicht beeinträchtigt.
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In dieser Arbeit wird die Entwicklung und experimentelle Umsetzung einer kontinuierlichen, kohärenten Lichtquelle im vakuumultravioletten Wellenlängenbereich um 122 nm präsentiert. Diese basiert auf der nichtlinearen optischen Summenfrequenzmischung dreier Fundamentallaserstrahlen in einer mit Quecksilberdampf gefüllten Hohlfaser. Die Wellenlängen der fundamentalen Laser sind dabei an der Niveaustruktur des Quecksilbers orientiert, um eine mehrfach resonante Überhöhung der nichtlinearen Suszeptibilität zu erreichen. Der transversale Einschluss der Lichtfelder in der Faser verlängert die Wechselwirkungszone mit dem nichtlinearen Medium um mehrere Größenordnungen gegenüber dem Regime fokussierter Strahlen und erlaubt so signifikante Steigerungen der Mischeffizienz.rnrnIm Zuge dieser Arbeit wurde neben einer umfassenden mathematischen Analyse des nichtlinearen Mischprozesses unter Einfluss der Fasercharakteristika eine Apparatur zur Erzeugung und Detektion vakuumultravioletter Strahlung entwickelt. Die Generierung ausreichend hoher Dampfdichten innerhalb des 50 µm durchmessenden Faserkerns konnten spektroskopisch nachgewiesen werden.rnrnDas erste erfolgreiche Summenfrequenzmischen zu 121,26 nm in der Faser wurde demonstriert. Die erzielten Mischeffizienzen sind bereits mit denen vergleichbar, welche unter Verwendung fokussierter Strahlen erreicht werden, obwohl eine Phasenanpassung in der Faser bisher nicht möglich war. Die Ergebnisse dieser Arbeit markieren damit einen wichtigen Schritt hin zu Leistungssteigerungen kohärenter, kontinuierlicher vakuumultravioletter Lichtquellen.rnrnEine solche Quelle wird für zukünftige Laserkühlung von magnetisch gefangenem Antiwasserstoff auf dem Lyman-Alpha Übergang, sowie die Rydberganregung von Calciumionen in einer Paulfalle zur Implementierung quantenlogischer Operationen benötigt.rnrnFerner hat eine Untersuchung der, für eine effiziente Konversion essentiellen, 6^1S_0 - 7^1S_0 Zwei-Photonen Resonanz in Quecksilber Hinweise auf eine bis dato experimentell nicht beobachtete, auf einer Mehr-Photonen Anregung beruhende Licht-induzierte Drift ergeben.
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Chemotherapy-induced neutropenia is a major risk factor for infection-related morbidity and mortality and also a significant dose-limiting toxicity in cancer treatment. Patients developing severe (grade 3/4) or febrile neutropenia (FN) during chemotherapy frequently receive dose reductions and/or delays to their chemotherapy. This may impact the success of treatment, particularly when treatment intent is either curative or to prolong survival. In Europe, prophylactic treatment with granulocyte-colony stimulating factors (G-CSFs), such as filgrastim (including approved biosimilars), lenograstim or pegfilgrastim is available to reduce the risk of chemotherapy-induced neutropenia. However, the use of G-CSF prophylactic treatment varies widely in clinical practice, both in the timing of therapy and in the patients to whom it is offered. The need for generally applicable, European-focused guidelines led to the formation of a European Guidelines Working Party by the European Organisation for Research and Treatment of Cancer (EORTC) and the publication in 2006 of guidelines for the use of G-CSF in adult cancer patients at risk of chemotherapy-induced FN. A new systematic literature review has been undertaken to ensure that recommendations are current and provide guidance on clinical practice in Europe. We recommend that patient-related adverse risk factors, such as elderly age (≥65 years) and neutrophil count be evaluated in the overall assessment of FN risk before administering each cycle of chemotherapy. It is important that after a previous episode of FN, patients receive prophylactic administration of G-CSF in subsequent cycles. We provide an expanded list of common chemotherapy regimens considered to have a high (≥20%) or intermediate (10-20%) risk of FN. Prophylactic G-CSF continues to be recommended in patients receiving a chemotherapy regimen with high risk of FN. When using a chemotherapy regimen associated with FN in 10-20% of patients, particular attention should be given to patient-related risk factors that may increase the overall risk of FN. In situations where dose-dense or dose-intense chemotherapy strategies have survival benefits, prophylactic G-CSF support is recommended. Similarly, if reductions in chemotherapy dose intensity or density are known to be associated with a poor prognosis, primary G-CSF prophylaxis may be used to maintain chemotherapy. Clinical evidence shows that filgrastim, lenograstim and pegfilgrastim have clinical efficacy and we recommend the use of any of these agents to prevent FN and FN-related complications where indicated. Filgrastim biosimilars are also approved for use in Europe. While other forms of G-CSF, including biosimilars, are administered by a course of daily injections, pegfilgrastim allows once-per-cycle administration. Choice of formulation remains a matter for individual clinical judgement. Evidence from multiple low level studies derived from audit data and clinical practice suggests that some patients receive suboptimal daily G-CSFs; the use of pegfilgrastim may avoid this problem.
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The newly developed atmosphere–ocean-chemistry-climate model SOCOL-MPIOM is presented by demonstrating the influence of the interactive chemistry module on the climate state and the variability. Therefore, we compare pre-industrial control simulations with (CHEM) and without (NOCHEM) interactive chemistry. In general, the influence of the chemistry on the mean state and the variability is small and mainly restricted to the stratosphere and mesosphere. The largest differences are found for the atmospheric dynamics in the polar regions, with slightly stronger northern and southern winter polar vortices in CHEM. The strengthening of the vortex is related to larger stratospheric temperature gradients, which are attributed to a parametrization of the absorption of ozone and oxygen in the Lyman-alpha, Schumann–Runge, Hartley, and Higgins bands. This effect is parametrized in the version with interactive chemistry only. A second reason for the temperature differences between CHEM and NOCHEM is related to diurnal variations in the ozone concentrations in the higher atmosphere, which are missing in NOCHEM. Furthermore, stratospheric water vapour concentrations differ substantially between the two experiments, but their effect on the temperatures is small. In both setups, the simulated intensity and variability of the northern polar vortex is inside the range of present day observations. Sudden stratospheric warming events are well reproduced in terms of their frequency, but the distribution amongst the winter months is too uniform. Additionally, the performance of SOCOL-MPIOM under changing external forcings is assessed for the period 1600–2000 using an ensemble of simulations driven by a spectral solar forcing reconstruction. The amplitude of the reconstruction is large in comparison to other state-of-the-art reconstructions, providing an upper limit for the importance of the solar signal. In the pre-industrial period (1600–1850) the simulated surface temperature trends are in reasonable agreement with temperature reconstructions, although the multi-decadal variability is more pronounced. This enhanced variability can be attributed to the variability in the solar forcing. The simulated temperature reductions during the Maunder Minimum are in the lowest probability range of the proxy records. During the Dalton Minimum, when also volcanic forcing is an important driver of temperature variations, the agreement is better. In the industrial period from 1850 onward SOCOL-MPIOM overestimates the temperature increase in comparison to observational data sets. Sensitivity simulations show that this overestimation can be attributed to the increasing trend in the solar forcing reconstruction that is used in this study and an additional warming induced by the simulated ozone changes.
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The aim of this study was to improve cage systems for maintaining adult honey bee (Apis mellifera L.) workers under in vitro laboratory conditions. To achieve this goal, we experimentally evaluated the impact of different cages, developed by scientists of the international research network COLOSS (Prevention of honey bee COlony LOSSes), on the physiology and survival of honey bees. We identified three cages that promoted good survival of honey bees. The bees from cages that exhibited greater survival had relatively lower titers of deformed wing virus, suggesting that deformed wing virus is a significant marker reflecting stress level and health status of the host. We also determined that a leak- and drip-proof feeder was an integral part of a cage system and a feeder modified from a 20-ml plastic syringe displayed the best result in providing steady food supply to bees. Finally, we also demonstrated that the addition of protein to the bees' diet could significantly increase the level ofvitellogenin gene expression and improve bees' survival. This international collaborative study represents a critical step toward improvement of cage designs and feeding regimes for honey bee laboratory experiments.