5,678 research outputs found

    Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

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    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, ν1+ν2+ν3+ν41+ν5−1\nu_1+\nu_2+\nu_3+\nu_4^1+\nu_5^{-1} in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) cm−1\text{cm}^{-1}, the rotational parameter BB was 1.162222 cm−1\text{cm}^{-1}, and the quartic centrifugal distortion parameter DD was 3.998(62)×10−6cm−1\times 10^{-6} \text{cm}^{-1}, where the numbers in the parenthesis are one-standard errors in the least significant digits

    Quality of Life After Axillary or Groin Sentinel Lymph Node Biopsy, With or Without Completion Lymph Node Dissection, in Patients With Cutaneous Melanoma

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    The aim of this study was to asses quality of life (QoL) after axillary or inguinal sentinel lymph node biopsy (SLNB) with or without completion lymph node dissection (CLND) in patients with cutaneous melanoma by comparing patients to a norm group of the general population and by comparing QoL between four patient groups depending on surgical procedure and location, i.e., patients receiving an axillary or groin SLNB, or an axillary or groin CLND.Between 1995 and 2003, a total of 242 axillary and inguinal SLNBs were performed. Of the 127 patients eligible for the study, 116 patients participated (91%). QoL was measured by the 30-item European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30), the McGill Pain Questionnaire and the Groningen Activity Restriction Scale.Median age at diagnosis was 50 (range, 18-77) years; median Breslow thickness 2.0 (range, 1-13) mm; median follow-up 56 (range, 4-94) months. SLNB only was performed in 89 patients (77%): 48 in the groin and 41 in the axilla. CLND was performed in 27 patients (23%): 13 in the axilla and 14 in the groin. More postoperative complications (13 vs. 5; P &lt;0.001) and lymphedema (10 vs. 8; P &lt;0.001) occurred in the CLND group than in the SLNB group. The total group of patients reported better physical (P &lt;0.001), role (P &lt;0.001), emotional (P &lt;0.001), and social functioning (P = 0.049), global QoL (P &lt;0.001), and less fatigue (P &lt;0.001) and pain (P &lt;0.001) than a German norm group. Analysis of variance revealed significant differences in role functioning (P = 0.02) and tendencies toward physical problems (P = 0.051) and fatigue (P = 0.051) between the four groups. Post hoc Bonferroni tests showed that the axillary CLND group had more problems than the axillary and inguinal SLNB groups. Kruskal-Wallis tests showed that the axillary CLND group reported most pain.QoL in melanoma survivors after axillary or inguinal SLNB with or without CLND was better than that in a norm group. Patients who underwent CLND in the axilla after SLNB reported most problems.</p

    The origin of peak-offsets in weak-lensing maps

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    Centroid positions of peaks identified in weak lensing mass maps often show offsets with respect to other means of identifying halo centres, like position of the brightest cluster galaxy or X-ray emission centroid. Here we study the effect of projected large-scale structure (LSS), smoothing of mass maps, and shape noise on the weak lensing peak positions. Additionally we compare the offsets in mass maps to those found in parametric model fits. Using ray-tracing simulations through the Millennium Run NN-body simulation, we find that projected LSS does not alter the weak-lensing peak position within the limits of our simulations' spatial resolution, which exceeds the typical resolution of weak lensing maps. We conclude that projected LSS, although a major contaminant for weak-lensing mass estimates, is not a source of confusion for identifying halo centres. The typically reported offsets in the literature are caused by a combination of shape noise and smoothing alone. This is true for centroid positions derived both from mass maps and model fits.Comment: 6 pages, 4 figures, accepted for publication in MNRAS, significant additions to v

    Methodological tests of the use of trace elements as tracers to assess root activity

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    peer-reviewedN.J.H. was funded by the Irish Research Council, co-funded by Marie Curie Actions under FP7. The field experiments A, B and G were supported by the European Community's Seventh Framework Programme (FP7/2007-2013) under the grant agreements FP7-266018 (AnimalChange) and FP7- 244983 (MultiSward). Experiment F was supported by the German Science Foundation (FOR 456).Background and aims There is increasing interest in how resource utilisation in grassland ecosystems is affected by changes in plant diversity and abiotic conditions. Research to date has mainly focussed on aboveground responses and there is limited insight into belowground processes. The aim of this study was to test a number of assumptions for the valid use of the trace elements caesium, lithium, rubidium and strontium as tracers to assess the root activity of several grassland species. Methods We carried out a series of experiments addressing the reliability of soil labelling, injection density, incubation time, application rate and the comparability of different tracers in a multiple tracer method. Results The results indicate that it is possible to achieve a reliable labelling of soil depths. Tracer injection density affected the variability but not the mean level of plant tracer concentrations. Tracer application rates should be based on pilot studies, because of site- and species-specific responses. The trace elements did not meet prerequisites to be used in a multiple tracer method. Conclusions The use of trace elements as tracers is potentially a very useful tool to give insight into plant root activity at different soil depths. This work highlights some of the main benefits and pitfalls of the method and provides specific recommendations to assist the design of tracer experiments and interpretation of the results.N.J.H. was funded by the Irish Research Council, co-funded by Marie Curie Actions under FP7. The field experiments A, B and G were supported by the European Community's Seventh Framework Programme (FP7/2007-2013) under the grant agreements FP7-266018 (AnimalChange) and FP7- 244983 (MultiSward). Experiment F was supported by the German Science Foundation (FOR 456).European Unio
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