497 research outputs found

    Translations of Steinhausen's Publications Provide Insight Into Their Contributions to Peripheral Vestibular Neuroscience

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    The quantitative relationship between angular head movement and semicircular canal function is most often referenced to the well-known torsion-pendulum model that predicts cupular displacement from input head acceleration. The foundation of this model can be traced back to Steinhausen's series of papers between 1927 and 1933 whereby he endeavored to document observations of cupular displacements that would directly infer movement of the endolymph resulting from angular rotation. He also was the first to establish the direct relationship between cupular displacement and compensatory eye movements. While the chronology of these findings, with their successes and pitfalls, are documented in Steinhausen's work, it reflects a fascinating journey that has been inaccessible to the non-German speaking community. Therefore, the present compilation of translations, with accompanying introduction and discussion, was undertaken to allow a larger component of the vestibular scientific community to gain insight into peripheral labyrinthine mechanics provided by this historical account

    Costs and cost trends for forestry practices in the South

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    Cost estimates of practicing forestry in the South during 1986 and cost changes during the 1952-1986 period are presented in this report. Albert C. Worrell reported the original cost study in Forest Farmer in May 1953. His work was updated by James G. Yoho and Robert B. Fish in the November 1961 issue of Forest Farmer. Other revisions include James G. Yoho, George F . Dutrow, and James Moak (Forest Farmer, 1971); James Moak and Jim Kucera (Forest Farmer, 1975); James Moak, James Kucera, and W.F. Watson (Forest Farmer Manual, 1977); James Moak, W.F. Watson, and Paul Van Deusen (Forest Farmer Manual, 1980); James Moak, W.F. Watson, and Mark Watson (Forest Farmer Manual, 1983); and Thomas J. Straka and William F . Watson (Forest Farmer Manual, 1985). The present study is based on the results of a survey completed in 1986 and reports current costs for most forestry practices covered by previous surveys. It also provides tables with cost changes from 1952 to 1986 for\u27 specific commercial practices common in the South

    Primer on forestry investment

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    Most forest farmers know that growing timber is a good investment. Some forest farmers, however, and many new timberland investors may not fully understand the basic ingredients that make up a forestry investment. Like other ventures, forest farming involves costs and revenues, and rates of return can be calculated. These rates can be compared with interest rates for other investments, but forest farming is not exactly like your other investments. It has special qualities

    Clean and Green Urban Water Bodies Benefit Nocturnal Flying Insects and Their Predators, Insectivorous Bats

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    Nocturnal arthropods form the prey base for many predators and are an integral part of complex food webs. However, there is limited understanding of the mechanisms influencing invertebrates at urban water bodies and the potential flow-on effects to their predators. This study aims to: (i) understand the importance of standing water bodies for nocturnal flying insect orders, including the landscape- and local-scale factors driving these patterns; and (ii) quantify the relationship between insects and insectivorous bats. We investigated nocturnal flying insects and insectivorous bats simultaneously at water bodies (n = 58) and non-water body sites (n = 35) using light traps and acoustic recorders in Melbourne, Australia. At the landscape scale, we found that the presence of water and high levels of surrounding greenness were important predictors for some insect orders. At the water body scale, low levels of sediment pollutants, increased riparian tree cover and water body size supported higher insect order richness and a greater abundance of Coleopterans and Trichopterans, respectively. Most bat species had a positive response to a high abundance of Lepidopterans, confirming the importance of this order in the diet of insectivorous bats. Fostering communities of nocturnal insects in urban environments can provide opportunities for enhancing the prey base of urban nocturnal insectivores.DFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

    It pays to know how your timber will be valued

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    You as a forest farmer can usually realize income from your timber investment in two ways. You can rent timberland for nontimber uses (usually hunting) , or you can lease or sell your interest in the timber. In most cases, greater returns result from selling timber outright

    Somatosensory Influence on Platform-Induced Translational Vestibulo-Ocular Reflex in Vertical Direction in Humans

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    The vestibulo-ocular reflex (VOR) consists of two components, the rotational VOR (rVOR) elicited by semicircular canal signals and the translational VOR (tVOR) elicited by otolith signals. Given the relevant role of the vertical tVOR in human walking, this study aimed at measuring the time delay of eye movements in relation to whole-body vertical translations in natural standing position. Twenty (13 females and 7 males) healthy, young subjects (mean 25 years) stood upright on a motor-driven platform and were exposed to sinusoidal movements while fixating a LED, positioned at a distance of 50 cm in front of the eyes. The platform motion induced a vertical translation of 2.6 cm that provoked counteracting eye movements similar to self-paced walking. The time differences between platform and eye movements indicated that the subject's timing of the extraocular motor reaction depended on stimulus frequency and number of repetitions. At low stimulus frequencies (<0.8 Hz) and small numbers of repetitions (<3), eye movements were phase advanced or in synchrony with platform movements. At higher stimulus frequencies or continuous stimulation, eye movements were phase lagged by ~40 ms. Interestingly, the timing of eye movements depended on the initial platform inclination. Starting with both feet in dorsiflexion, eye movements preceded platform movements by 137 ms, whereas starting with both feet in plantar flexion eye movement precession was only 19 ms. This suggests a remarkable influence of foot proprioceptive signals on the timing of eye movements, indicating that the dynamics of the vertical tVOR is controlled by somatosensory signals

    Determination of intrarenal resistance index (RI) in patients with multiple myeloma

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    <p>Abstract</p> <p>Background</p> <p>Renal impairment is a common complication of multiple myeloma occuring in up to 50% of patients at some stage in their disease. Due to occurrence of cast nephropathies we hypothesized circulatory dysregulation (vasoconstriction) in the kidneys with measurable elevation of the resistance index among these patients which would have a diagnostic impact.</p> <p>Subjects and methods</p> <p>36 patients with treated multiple myeloma (21 females, 15 males, mean age 61.6 ± 8.5 years) were prospectively examined by conventional abdominal ultrasound with focussed investigation of the kidneys. First, length of the organs, parenchymal width and characterization of parenchymal echogenicity were determined. Then, intrarenal RI values were measured in segmental and arcuate arteries, respectively, in both kidneys. Additionally, serum creatinine, BUN and GFR of each patient were evaluated. RI values were compared to values of 78 healthy control subjects.</p> <p>Results</p> <p>Mean renal RI was 0.68 ± 0.07 which was slightly higher than in controls with 0.62 ± 0.05, but without statistical significance. Due to the laboratory analyses patients were subdivided in those with normal (group 1, n = 21) and those with impaired (group 2, n = 15) renal function. In both groups kidney size and parenchymal width were normal. Significant more group 2 patients (60%) revealed hyperechogenic par enchyma than group 1 patients (24%) (p < 0.01). Mean renal RI indices were 0.67 ± 0.06 (right) and 0.69 ± 0.06 (left) in group 1 patients and 0.71 ± 0.08 (right) and 0.71 ± 0.07 (left) in group 2 patients and showed no significant difference (p = 0.06 and 0.15).</p> <p>Conclusion</p> <p>Renal RI values are not significantly elevated in patients with multiple myeloma even in those with renal impairment so that no hints to a relevant vasoconstriction could be evaluated. RI seems not to be a relevant parameter for the diagnosis of cast nephro pathy of multiple myeloma patients. Routinely performed ultrasound examination should be more focussed on the qualification of parenchymal echogenicity.</p

    Asteroseismology across the HR diagram

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    High precision spectroscopy provides essential information necessary to fully exploit the opportunity of probing the internal structure of stars using Asteroseismology. In this work we discuss how Asteroseismology combined with High Precision Spectroscopy can establish a detailed view on stellar structure and evolution of stars across the HR diagramme.Comment: 6 pages, 2 figures - to appear in Precision Spectroscopy in Astrophysics, (Eds) L. Pasquini, M. Romaniello, N.C. Santos, and A. Correia, ESO Astrophysics Symposia, 200

    Space and Ground Based Pulsation Data of Eta Bootis Explained with Stellar Models Including Turbulence

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    The space telescope MOST is now providing us with extremely accurate low frequency p-mode oscillation data for the star Eta Boo. We demonstrate in this paper that these data, when combined with ground based measurements of the high frequency p-mode spectrum, can be reproduced with stellar models that include the effects of turbulence in their outer layers. Without turbulence, the l=0 modes of our models deviate from either the ground based or the space data by about 1.5-4.0 micro Hz. This discrepancy can be completely removed by including turbulence in the models and we can exactly match 12 out of 13 MOST frequencies that we identified as l=0 modes in addition to 13 out of 21 ground based frequencies within their observational 2 sigma tolerances. The better agreement between model frequencies and observed ones depends for the most part on the turbulent kinetic energy which was taken from a 3D convection simulation for the Sun.Comment: 13 pages, 7 figures, ApJ in pres

    On the interpretation of echelle diagrams for solar-like oscillations. Effect of centrifugal distortion

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    This work aims at determining the impact of slow to moderate rotation on the regular patterns often present in solar-like oscillation spectra. We focus on the well-known asteroseismic diagnostic echelle diagrams, examining how rotation may modify the estimates of the large and small spacings, as well as the identification of modes. We illustrate the work with a real case: the solar-like star η\eta Bootis. The modeling takes into account rotation effects on the equilibrium models through an effective gravity and on the oscillation frequencies through both perturbative and non-perturbative calculations. We compare the results of both type of calculations in the context of the regular spacings (like the small spacings and the scaled small spacings) and echelle diagrams. We show that for echelle diagrams the perturbative approach remains valid for rotational velocities up to 40-50 km/s. We show that for the rotational velocities measured in solar-like stars, theoretical oscillation frequencies must be corrected up to the second-order in terms of rotation rate, including near degeneracy effects. For rotational velocities of about 16 km/S and higher, diagnostics on large spacings and on modal identification through echelle diagrams can be significantly altered by the presence of the m≠0m\neq0 components of the rotationally split modes. We found these effects to be detectable in the observed frequency range. Analysis of the effects of rotation on small spacings and scaled small spacings reveals that these can be of the order of, or even larger than surface effects, typically turbulence, microscopic diffusion, etc. Furthermore, we show that scaled spacings are significantly affected by stellar distortion even for small stellar rotational velocities (from 10-15 km/s) and therefore some care must be taken when using them as indicators for probing deep stellar interiors.Comment: 10 pages,5 figures, accepted for publication in ApJ; http://iopscience.iop.org/0004-637X/721/1/537
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