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  • Articles  (11,441)
  • Springer  (8,829)
  • National Academy of Sciences  (2,612)
  • 1995-1999  (11,441)
  • 1975-1979
  • 1995  (11,441)
  • Medicine  (10,683)
  • Architecture, Civil Engineering, Surveying  (758)
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  • Articles  (11,441)
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  • 1995-1999  (11,441)
  • 1975-1979
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  • 1
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    GPS solutions 1 (1995), S. 3-4 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
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  • 2
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    GPS solutions 1 (1995), S. 1-2 
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  • 3
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    GPS solutions 1 (1995), S. 11-12 
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  • 4
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    GPS solutions 1 (1995), S. 7-8 
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  • 5
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    GPS solutions 1 (1995), S. 5-6 
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  • 6
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    GPS solutions 1 (1995), S. 9-10 
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  • 7
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    GPS solutions 1 (1995), S. 81-81 
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  • 8
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    GPS solutions 1 (1995), S. 86-87 
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  • 9
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    GPS solutions 1 (1995), S. 90-90 
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  • 10
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    GPS solutions 1 (1995), S. 91-93 
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  • 11
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    GPS solutions 1 (1995), S. 94-95 
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  • 12
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    GPS solutions 1 (1995), S. 88-89 
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  • 13
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    GPS solutions 1 (1995), S. 108-112 
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  • 14
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    GPS solutions 1 (1995), S. 99-107 
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  • 15
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    GPS solutions 1 (1995), S. 96-98 
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  • 16
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    GPS solutions 1 (1995), S. 129-138 
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  • 17
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    GPS solutions 1 (1995), S. 121-128 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: In the previous article we covered what asset location systems (ALS) are and the features and benefits they offer. In this article we explore the various features to be considered when acquiring an ALS and steps to be taken. We discuss what users are saying they want in an ALS, including the results of a survey of vehicle tracking system users and providers.
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  • 18
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    GPS solutions 1 (1995), S. 139-142 
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  • 19
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    GPS solutions 1 (1995), S. 113-120 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: Abstract The vertical component obtained from the Global Positioning System (GPS) observations is from the ellipsoid (a mathematical surface), and therefore needs to be converted to the orthometric height, which is from the geoid (represented by the mean sea level). The common practice is to use existing bench marks (around the four corners of a project area and interpolate for the rest of the area), but in many areas bench marks may not be available, in which case an existing geoid undulation is used. Present available global geoid undulation values are not generally as detailed as needed, and in many areas they are not known better than ±1 to ±5 m, because of many limitations. This article explains the difficulties encountered in obtaining precise geoid undulation with some example computations, and proposes a technique of applying corrections to the best available global geoid undulations using detailed free-air gravity anomalies (within a 2° × 2° area) to get relative centimeter accuracy. Several test computations have been performed to decide the optimal block sizes and the effective spherical distances to compute the regional and the local effects of gravity anomalies on geoid undulations by using the Stokes integral. In one test computation a 2° × 2° area was subdivided into smaller surface elements. A difference of 37.34 ± 1.6 cm in geoid undulation was obtained over the same 2° × 2° area when 1° × 1° block sizes were replaced by a combination of 5' × 5' and 1' × 1' subdivision integration elements (block sizes).
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  • 20
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    GPS solutions 1 (1995), S. 143-144 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
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  • 21
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    GPS solutions 1 (1995), S. 145-146 
    ISSN: 1521-1886
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  • 22
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    GPS solutions 1 (1995), S. 148-149 
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  • 23
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    GPS solutions 1 (1995), S. 146-146 
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  • 24
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    GPS solutions 1 (1995), S. 23-27 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: This is the first in a series of three articles authored by John Beukers. In this series, John will lead us through some of today's relevant radionavigation history putting turbulent times into perspective. Picking out what he considers significant in the current debate, he projects the future for satellite and terrestrial radionavigation systems well into the 21st century.
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  • 25
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    GPS solutions 1 (1995), S. 48-53 
    ISSN: 1521-1886
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  • 26
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    GPS solutions 1 (1995), S. 38-47 
    ISSN: 1521-1886
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  • 27
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    GPS solutions 1 (1995), S. 54-58 
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  • 28
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    GPS solutions 1 (1995), S. 59-64 
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  • 29
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    GPS solutions 1 (1995), S. 13-22 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: Asset location systems, including vehicle and property tracking systems, are in the verge of exploding onto the scene for widespread business and personal use. This is due in part to decreased costs of GPS equipment, and greater availability of wireless communication systems, but also largely due to public awareness of their capabilities and benefits. Companies, organizations, and individual consumers that earlier could not justify the costs of tracking systems are now seriously considering their implementation. Public awareness of such systems is growing daily. Newspapers regularly have articles covering the latest applications of GPS. En route nagivation for aircraft, assisting blind people to navigate the streets of a city, and tracking skiers on slopes are some of the topics of recent newspapers articles on GPS. This article explores GPS asset location systems, looks at their features and foibles, and considers their cost, utility, ease of use, and drawbacks.
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  • 30
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    GPS solutions 1 (1995), S. 28-37 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: Executive Summary GPS is a scientific method used as an adjunct to geographic information systems (GIS) for determining high-accuracy control points over large areas. Recent improvements in receiver technology, differential surveying, and software have made use of GPS technology more practical for smaller GIS projects. This article compares three different GPSs with occupation times of 2 and 12 min using an existing control network, comparing the location of the points and the distances between points. The control network internal distances vary from 40 to 280 m, and within 2000 m of the nearest second-order National Geodetic Survey (NGS) triangulation station. The partnership of GPS and GIS will lead to higher surveying integrity while improving digital mapping on the ground over small and large areas. It also allows for postsurvey analysis with solutions coming from multiple base stations. Presented here is a case study of how to achieve highly accurate and effective control points using using GPS/GIS, particularly for a small area.
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  • 31
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    GPS solutions 1 (1995), S. 65-73 
    ISSN: 1521-1886
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Geosciences
    Notes: The NAVSTAR Global Positioning System is a space-based, all-weather, worldwide satellite navigation system. GPS uses the constellation of satellites and associated ground equipment to perform the primary missions of highly accurate navigation, time transfer, and nuclear detonation detection. To achieve these missions, GPS has three clearly defined segments – space, user and control (see Figure 1). The control segment, otherwise referred to as the operational control segment (OCS), consists of the personnel and equipment that controls the space segment and interfaces with the user segment. The OCS is made up of the master control station (MCS), the ground antennas (GA), and the monitor stations (MS). The purpose of this article is to describe how the 2nd Space Operations Squadron runs the MCS, the key element of the OCS.
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  • 32
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    GPS solutions 1 (1995), S. 74-75 
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  • 33
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    GPS solutions 1 (1995), S. 76-79 
    ISSN: 1521-1886
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  • 34
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    GPS solutions 1 (1995), S. 80-80 
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  • 35
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    GPS solutions 1 (1995), S. 85-85 
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  • 36
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    Stochastic environmental research and risk assessment 9 (1995), S. 33-47 
    ISSN: 1436-3259
    Keywords: Hidden markov models ; maximum likelihood estimation ; EM algorithm ; martingale estimating function ; forward-backward algorithm ; Monte Carlo ; filtering ; Nash cascade model ; rainfall runoff modeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Many stochastic process models for environmental data sets assume a process of relatively simple structure which is in some sense partially observed. That is, there is an underlying process (Xn, n ≥ 0) or (Xt, t ≥ 0) for which the parameters are of interest and physically meaningful, and an observable process (Yn, n ≥ 0) or (Yt, t ≥ 0) which depends on the X process but not otherwise on those parameters. Examples are wide ranging: the Y process may be the X process with missing observations; the Y process may be the X process observed with a noise component; the X process might constitute a random environment for the Y process, as with hidden Markov models; the Y process might be a lower dimensional function or reduction of the X process. In principle, maximum likelihood estimation for the X process parameters can be carried out by some form of the EM algorithm applied to the Y process data. In the paper we review some current methods for exact and approximate maximum likelihood estimation. We illustrate some of the issues by considering how to estimate the parameters of a stochastic Nash cascade model for runoff. In the case of k reservoirs, the outputs of these reservoirs form a k dimensional vector Markov process, of which only the kth coordinate process is observed, usually at a discrete sample of time points.
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  • 37
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    Stochastic environmental research and risk assessment 9 (1995), S. 117-132 
    ISSN: 1436-3259
    Keywords: River Quality ; network ; computer model ; Thermodynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract In this paper, concepts of network thermodynamics are applied to a river water quality model, which is based on Streeter-Phelps equations, to identify the corresponding physical components and their topology. Then, the randomness in the parameters, input coefficients and initial conditions are modeled by Gaussian white noises. From the stochastic components of the physical system description of problem and concepts of physical system theory, a set of stochastic differential equations can be automatically generated in a computer and the recent developments on the automatic formulation of the moment equations based on Ito calculus can be used. This procedure is illustrated through the solution of an example of stochastic river water quality problem and it is also shown how other related problems with different configurations can be automatically solved in a computer using just one software.
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  • 38
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    Stochastic environmental research and risk assessment 9 (1995), S. 171-205 
    ISSN: 1436-3259
    Keywords: AR-AIC-Bayes filter ; autoregressive spectral density estimation ; diagnostic checks for ARMA models ; exploratory data analysis ; fast Fourier transform ; Hurst coefficient ; long-memory times series ; periodogram smoothing ; riverflow time series ; spectral density plots
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Current methods of estimation of the univariate spectral density are reviewed and some improvements are made. It is suggested that spectral analysis may perhaps be best thought of as another exploratory data analysis (EDA) tool which complements, rather than competes with, the popular ARMA model building approach. A new diagnostic check for ARMA model adequacy based on the nonparametric spectral density is introduced. Additionally, two new algorithms for fast computation of the autoregressive spectral density function are presented. For improving interpretation of results, a new style of plotting the spectral density function is suggested. Exploratory spectral analyses of a number of hydrological time series are performed and some interesting periodicities are suggested for further investigation. The application of spectral analysis to determine the possible existence of long memory in natural time series is discussed with respect to long riverflow, treering and mud varve series. Moreover, a comparison of the estimated spectral densities suggests the ARMA models fitted previously to these datasets adequately describe the low frequency component. Finally, the software and data used in this paper are available by anonymous ftp from fisher.stats.uwo.ca.
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  • 39
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    Stochastic environmental research and risk assessment 9 (1995), S. 215-237 
    ISSN: 1436-3259
    Keywords: Computation ; discretization ; entropy ; networks ; time averaging ; water quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The computational aspects of using a new, entropy-based, theory to predict water quality values at discontinued water quality monitoring stations are discussed. The main computational issues addressed are the level of discretization used in converting the continuous probability distribution of water quality values to the discrete levels required for the entropy function, and the choice of the interval of time for which to assign the value of the water quality (period of time averaging) through the entropy function. Unlike most cases of entropy applications involving discretization of continuous functions the results of using entropy theory to predict water quality values at discontinued monitoring stations in this application appear to be insensitive to the choice of the level of discretization even down to the very coarse level discretization associated with only eight intervals. However, depending on the length of record available the choice of the time interval for which the water quality values are assigned (period for time averaging) appear to have a significant impact on the accuracy of the results.
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  • 40
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    Stochastic environmental research and risk assessment 9 (1995), S. 13-32 
    ISSN: 1436-3259
    Keywords: Distributed parameter filter ; shallow water equations ; distributed dynamical systems ; data assimilation ; white Gaussian noise
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Distributed parameter filtering theory is employed for estimating the state variables and associated error covariances of a dynamical distributed system under highly random tidal and meteorological influences. The stochastic-deterministic mathematical model of the physical system under study consists of the shallow water equations described by the momentum and continuity equations in which the external forces such as Coriolis force, wind friction, and atmospheric pressure are considered. White Gaussian noises in the system and measurement equations are used to account for the inherent stochasticity of the system. By using an optimal distributed parameter filter, the information provided by the stochastic dynamical model and the noisy measurements taken from the actual system are combined to obtain an optimal estimate of the state of the system, which in turn is used as the initial condition for the prediction procedure. The approach followed here has numerical approximation carried out at the end, which means that the numerical discretization is performed in the filtering equations, and not in the equations modelling the system. Therefore, the continuous distributed nature of the original system is maintained as long as possible and the propagation of modelling errors in the problem is minimized. The appropriateness of the distributed parameter filter is demonstrated in an application involving the prediction of storm surges in the North Sea. The results confirm excellent filter performance with considerable improvement with respect to the deterministic prediction.
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    Stochastic environmental research and risk assessment 9 (1995), S. 77-88 
    ISSN: 1436-3259
    Keywords: Extreme rainfalls ; partial duration series ; regional estimation ; Bayes' theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Based on the Partial Duration Series model a regional Bayesian approach is introduced in the modelling of extreme rainfalls from a country-wide system of recording raingauges in Denmark. The application of the Bayesian principles is derived in case of both exponential and generalized Pareto-distributed exceedances. The method is applied to, respectively, the total precipitation depth and the maximum 10 minutes rain intensity of individual storms from 41 stations. By means of the regional analysis prior distributions of the parameters in the Partial Duration Series model are estimated. It is shown that the regional approach significantly reduces the uncertainty of the T-year event estimator compared to estimation based solely on at-site data. In addition, the regional approach provides quantile estimates at non-monitored sites.
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  • 42
    ISSN: 1436-6215
    Keywords: Kraftsportler ; hohe Proteinzufuhr ; renale Nettosäureausscheidung ; Urin pH ; Ammoniumausscheidung ; Ammoniumproduktion ; renale Säureausscheidungskapazität ; Sulfat ; Bodybuilder ; high protein diet ; renal net acid excretion ; urine-pH ; ammonium excretion ; ammonia production ; sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Bodybuilders often prefer a high protein diet to achieve maximum skeletal muscle hypertrophy. In this study the effect of a high protein diet on renal acid load and renal handling of proton excretion was studied comparing dietary intake and urinary ionograms in 37 male bodybuilders and 20 young male adults. Energy intake (+7 %), protein intake (128 vs 88 g/d/1.73 m2), and renal net acid excretion (95 vs 64 mmol/d/1.73 m2) were higher in the bodybuilders than in the controls, however, urine-pH was only slightly lower (5.83 vs 6.12). In the bodybuilders renal ammonium excretion was higher at any given value of urine pH than in the controls. In a regression analysis protein intake proved to be an independent factor modulating the ratio between urine-pH and renal ammonium excretion. The concomitant increase of renal net acid excretion and maximum renal acid excretion capacity in periods of high protein intake appears to be a highly effective response of the kidney to a specific food intake leaving a large renal surplus capacity for an additional renal acid load.
    Notes: Zusammenfassung Kraftsportler ernähren sich zur Förderung des Muskelwachstums häufig proteinreich. In dieser Studie wurde die Wirkung einer hohen Proteinzufuhr auf die renale Säurelast und die renale Säureausscheidungskapazität anhand des Vergleichs der Daten der Nährstoffzufuhr und der Harnionogramme von 37 Kraftsportlern mit hoher Proteinzufuhr und 20 jungen Erwachsenen mit normaler Proteinzufuhr (Vergleichsgruppe) untersucht. Die Kraftsportler zeigten eine höhere Energie-(+7 %) und Proteinzufuhr (128 vs 88 g/d/1.73 m2) und eine höhere renale Nettosäureausscheidung (95 vs 64 mmol/d/1.73 m2) als die Vergleichsgruppe. Die Differenz der Urin pH-Werte der beiden Gruppen war allerdings erstaunlich gering (5.83 vs 6.12). Bei den Kraftsportlern war die renale Ammoniumausscheidung bei allen Urin pH-Werten deutlich höher als bei der Vergleichsgruppe. Eine Regressions-analyse ergab, daß die Proteinzufuhr das Verhältnis von Urin pH und renaler Ammoniumausscheidung eigenständig zu beeinflussen vermag. Eine vermehrte Proteinzufuhr führt zu einer erhöhten renalen Säurelast und Nettosäureausscheidung. Die gleichzeitig auftretende Steigerung der renalen Säureausscheidungskapazität infolge einer erhöhten Ammoniumproduktion stellt einen sinnvollen Anpassungsmechanismus des Körpers an diese besondere Form der Ernährung dar, der dem Körper eine ausreichende funktionelle Reservekapazität für weitere den Säure-Basen-Haushalt belastende pathophysiologische Ereignisse erhält.
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    European journal of nutrition 34 (1995), S. 160-163 
    ISSN: 1436-6215
    Keywords: Immunglobulin G ; Dotterantikörper ; Intestinale Absorption ; Kalb ; Immunoglobulin G ; yolk antibodies ; intestinal absorption ; calf
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Studying the prophylactic effects of specific yolk antibodies against diarrhea in newborn calves, also the intestinal absorption of unspecific heterogeneous avian antibodies as well as their effects on the uptake of maternal bovine colostral antibodies (bIgG) was investigated. Two groups of newborn calves received egg powder (16 g or 8 g per day) for the first 10 days of their life beginning with the first meal. A third group was kept as a control without any egg powder in their diet. Blood samples (5 to 10 calves per sampling time) were taken from 123 calves at 6, 12, 24, 48, or 96 h postnatally. With both doses the highest chicken IgG (cIgG) levels (3.1 µg resp. 1.2 µg per ml serum) have been measured 12 h after birth. These concentrations decreased continuously to the levels of 1.1 µg resp. 0.2 µg cIgG per ml serum at 96 h postnatally. The uptake into blood at 6 h postnatally has roughly been estimated as approximately 23 % (bIgG) and 7 % resp. 6 % (cIgG) of the IgG dosages given with the first meal. The time-course (6 to 96 h) of the bIgG level in blood was quite stable, plateauing already after 6 h at a mean of 5.9 mg per ml serum. Significant differences between the bIgG levels of calves with yolk antibodies in their diet (6.2 resp. 6.1 mg bIgG per ml serum) and those of the control group (5.4 mg per ml serum) could not be observed. Obviously, the prophylactic use of egg powder in newborn calves has no negative effect on the absorption of colostral antibodies. However, with the feeding of chicken egg yolk antibodies already with the first meal also the absorption of avian antibodies has to be taken into consideration.
    Notes: Zusammenfassung Im Rahmen einer Untersuchung zur prophylaktischen Wirksamkeit von spezifischen Dotterantikörpern bei erregerbedingten Kälberdurchfällen wurde auch die Absorption der unspezifischen heterologen aviären Dotterantikörper (cIgG) und deren Wirkung auf die Aufnahme von maternalen bovinen Kolostrumantikörpern (bIgG) überprüft. Zwei Gruppen von neugeborenen Kälbern wurde sprühgetrocknetes Volleipulver ab der ersten Tränke in einer Dosierung entweder von 16 g oder von 8 g pro Tag während der ersten 10 Lebenstage verabreicht. Eine dritte Gruppe diente als Kontrolle und erhielt kein Eipulver. Von insgesamt 123 Kälbern (5 bis 10 Kälber pro Entnahmezeitpunkt) wurden 6, 12, 24, 48, 72 bzw. 96 Stunden post natum Blutproben genommen. Bei beiden Eipulverdosierungen wurden die höchsten Hühner-IgG-Konzentrationen (3,1 µg bzw. 1,2 µg pro ml Serum) jeweils 12 Stunden post natum ermittelt. Diese cIgG-Konzentrationen nahmen danach kontinuierlich auf Konzentrationen von 1,1 µg bzw. 0,2 µg pro ml Serum zum Zeitpunkt 96 Stunden post natum ab. Bezogen auf die mit der ersten Tränke verabreichte bIgG- bzw. cIgG-Menge wurde überschlagsweise zum Zeitpunkt 6te Lebensstunde eine Anflutung im Blut von 23 % (bIgG) bzw. von 7 % und 6 % (cIgG) errechnet. Der zeitliche Verlauf (6te bis 96te Stunde) der Konzentration des bovinen IgGs in den Blutproben war vergleichsweise stabil und lag durchschnittlich bei 5,9 mg pro ml Serum, wobei das Plateau bereits nach 6 Stunden erreicht war. Signifikante Unterschiede zwischen den bIgG-Werten der Kälber, die Dotterantikörper bekamen (6,2 bzw. 6,1 mg pro ml Serum), und denen der Kontrollgruppe (5,4 mg pro ml Serum) waren nicht zu beobachten. Eipulver kann somit offensichtlich zur Prophylaxe bei neugeborenen Kälbern ohne Beeinträchtigung der Absorption der kolostralen Antikörper verabreicht werden. Allerdings muß bei einer Eipulververgabe mit der ersten Tränke auch mit einer Absorption von aviären Dotterantikörpern gerechnet werden.
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  • 44
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    European journal of nutrition 34 (1995), S. 190-197 
    ISSN: 1436-6215
    Keywords: Verzehrserhebungen ; Nationale Verzehrsstudie ; Lebensmittelverzehr ; internationaler Vergleich von Verzehrserhebungen ; Dietary surveys ; national food consumption study ; food intake ; international comparison of dietary surveys
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Referring to the data of the National Food Consumption Study in Germany and the Dietary and Nutritional Survey of British Adults, this article compares the food intake of German and British adults. Such a comparison is possible because both studies have mainly the same methodology. The comparison of the food intake of German and British adults points out food groups which Germans consume inhigher amounts than British people do. To this category belong meat products and sausages, eggs, cheese and cottage cheese, butter, fat for cooking and salad oil, bread and pastries, vegetables, fruit, preserves and soft drinks. The Germans consumeless meat, fish and fish products, milk and milk products, pasta, rice and miscellaneous cereals, potatoes, sugar, sweets and tea than the British people do. The consumption of fruit products, alcoholic beverages and coffee is nearly the same in Germany and Great Britain.
    Notes: Zusammenfassung Anhand der Nationalen Verzehrsstudie und des „Dietary and Nutritional Survey of British Adults“ wird der Lebensmittelverzehr der Erwachsenen in Deutschland und Großbritannien verglichen. Dies ist möglich, weil die Methodik weitgehend übereinstimmt. Beim Vergleich des Lebensmittelverzehrs von Deutschen und Briten fallen Lebensmittel auf, von denen die Deutschenmehr zu sich nehmen als die Briten. Dazu gehören Fleisch- und Wurstwaren, Eier, Käse und Quark, Butter, Speisefette und -öle, Brot und Backwaren, Gemüse, Obst, Marmelade/Konfitüre und alkoholfreie Getränke. Die Deutschen nehmen dagegenweniger Fleisch, Fisch und Fischwaren, Milch und Milchprodukte, Nährmittel, Kartoffeln, Zucker, Süßwaren und Tee zu sich als die Briten. Beim Konsum von Obstprodukten, alkoholischen Getränken und Röstkaffee herrschen nur geringfügige Unterschiede zwischen Deutschen und Briten.
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  • 45
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    European journal of nutrition 34 (1995), S. 206-213 
    ISSN: 1436-6215
    Keywords: Fischöl ; Olivenöl ; Überernährung ; Sauen ; Energiebilanz ; Thermogenese ; Gaswechsel ; Fish oil ; olive oil ; overfeeding ; sows ; energy balance ; thermogenesis ; gaseous exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary A trial on total metabolism was conducted in eight nonpregnant, nonlactating sows over eight periods, each of 16 days duration, to measure potential fatty acid induced thermogenesis. During the first and last experimental periods, the animals received a basal ration which just covered the energy maintenance requirement. In the second to seventh periods supplements of olive oil, fish oil, or puffed wheat starch as reference nutrient were added to the diet in random sequence at two levels up to 50 % above the maintenance requirement. All rations were calculated with reference to the sows' initial weight and remained quantitatively unchanged throughout the experiment. The animals were fed twice daily. During each metabolism period a complete energy balance was assessed for all sows by means of collection technique (feed, feces, urine), and 48-h measurements of the gas exchange in a respiration chamber. The sows' body mass increased linearly during the course of the experiment by 5.8 kg per period. The three supplement types had no influence on the animals' final body weight, wich averaged 205.5 kg with the starch supplement, 204.8 kg with olive oil, and 205.8 kg with fish oil. Energy digestibility (DE/GE) was 100 % for all three supplements, and metabolizability of energy (ME/GE) one percentage point less. Carbon and energy depositions showed a pronounced linear relationship to the level of supplementation and were also influenced by the type of supplement. Heat production was 20.9 MJ/d after feeding the basal ration alone and, taking the average of the two supplementation levels, 21.6 MJ for the starch supplement, 21.0 MJ for olive oil, and 20.6 MJ for fish oil. The relationship between energy deposition and the supply of ME resulted in regression coefficients of 0.9 MJ/MJ after feeding starch and 1.0 MJ/MJ after feeding the two oils. It can be concluded from these results that supplementation of the diet with fat containing mono- or polyunsaturated fatty acids above the energetic maintenance requirement under conditions of severely restricted movement (respiration chamber) has no influence on thermogenesis and consequently causes a deposition of energy equivalent to the amount supplied with the dietary fat.
    Notes: Zusammenfassung Zur Messung einer fettsäureninduzierten Thermogenese wurde ein Gesamtstoffwechselversuch mit 8 nichtgraviden, nichtlaktierenden Sauen über 8 Perioden von jeweils 16 Tagen Dauer durchgeführt. Die Tiere erhielten in der ersten und letzten Versuchsperiode eine den energetischen Erhaltungsbedarf deckende Grundration. In Periode 2 bis 7 wurden in zufälliger Reihenfolge Olivenöl, Fischöl bzw. als Referenznährstoff Weizenquellstärke in jeweils 2 Mengenstufen bis 50 % über das Erhaltungsniveau zugelegt. Alle Rationen wurden aufgrund der Anfangsmasse der Sauen eingestellt und über den gesamten Versuch in unveränderter Menge beibehalten. Die Fütterung erfolgte zweimal täglich. Von allen Tieren wurde in jeder Stoffwechselperiode eine vollständige Bilanzmessung mit Sammeltechnik (Futter, Kot, Harn) und 48stündiger Messung des Gaswechsels in der Respirationskammer durchgeführt. Die Körpermasse der Sauen stieg im Versuchsablauf linear um 5,8 kg je Zulageperiode an. Die drei Zulagearten hatten keinen Einfluß auf die Körpermasse der Tiere, sie wogen im Mittel bei Stärkezulage 205,5 kg, bei Olivenöl und Fischöl 204,8 bzw. 205,8 kg. Die Verdaulichkeit der Energie (DE/GE) betrug bei allen drei Zulagen 100 %, die Umsetzbarkeit der Energie (ME/GE) einen Prozentpunkt weniger. Der Kohlenstoffund Energieansatz zeigte eine ausgeprägte lineare Abhängigkeit zur Zulagenhöhe sowie einen signifikanten Effekt der Zulagenart. Die Wärmebildung betrug bei alleiniger Fütterung der Grundration 20,9 MJ und im Mittel der beiden Zulagestufen bei Stärkefütterung 21,6 MJ und bei Olivenöl und Fischöl 21,0 bzw. 20,6 MJ/d. Die Abhängigkeit des Energieansatzes von der Zufuhr an ME ergab Regressionskoeffizienten von 0,9 MJ/MJ bei Verabreichung von Stärke und 1,0 MJ/MJ bei Fütterung der beiden Öle. Aus den Ergebnissen ist zu folgern, daß eine Zulage von Fetten mit einfach oder mehrfach ungesättigten Fettsäuren über dem energetischen Erhaltungsbedarf unter der Bedingung stark eingeschränkter Bewegungsaktivität (Respirationskammer) keinen Einfluß auf die Thermogenese und somit einen energetischen Ansatz entsprechend der zugeführten Energie des Nahrungsfettes bewirkt.
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  • 46
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    European journal of nutrition 34 (1995), S. 269-276 
    ISSN: 1436-6215
    Keywords: Iod ; Uriniod ; Quotient Uriniod/Urinkreatinin ; Iodresorption ; Iodbioverfügbarkeit ; Nahrungsiod ; Iodine ; urinary iodine ; quotient iodine in urine/creatinine in urine ; iodine absorption ; iodine bioavailability ; alimentary iodine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The standard food for our volunteers, prepared in the central kitchen of the University Hospital of Tuebingen, consisted of breakfast, warm lunch and cold supper and contained, on average, approximately 230 µg of iodine/day. It is generally assumed that an equilibrium is established between iodine intake from food and urinary iodine excretion. Hence, the amount of iodine excreted with the urine within 24 h may reflect the daily ingestion of iodine. The fecal iodine losses are considered negligible. The alimentary iodine supply from food of our clinic would meet the WHO recommendations of 〉150 µg/day to prevent iodine-deficiency goiters. In 27 healthy volunteers the daily uptake of iodine was determined and the urinary excretion of iodine within 24 h was measured. Unexpectedly, only 16 % to 18 % of the alimentary iodine were excreted with the urine. Hence, the utilization of iodine from the food appears to be limited and therefore cannot prevent goiters in goiter areas. In addition, it was found that the correlation between urinary excretion of iodine and urinary excretion of creatinine is not a reliable parameter for the real daily excretion of iodine and iodine balance.
    Notes: Zusammenfassung Die Verpflegung (Frühstück, Mittagessen und Abendessen) aus der Zentralküche des Universitätsklinikums in Tübingen enthält durchschnittlich 230 µg Iod/Tag. Bei Personen, die täglich an dieser Verpflegung teilnehmen, stellt sich ein Gleichgewicht zwischen Iodaufnahme und renaler Iodausscheidung ein. Die Iodausscheidung über die Faeces gilt als vernachlässigbar. Die in unserer Klinikverpflegung angebotene Iodmenge entspricht dem von der WHO geforderten Angebot von 〉150 µg Iod/Tag, um endemische Strumen zu verhindern. Bei 27 gesunden Probanden wurden die tägliche Iodaufnahme und die zugehörige Ausscheidung von Iod im 24-h-Urin ermittelt. Dabei zeigte sich überraschend, daß vom angebotenen Iod nur 16 % bis 18 % mit dem Urin ausgeschieden wurden. Das mit der Nahrung angebotene Iod steht offenbar dem Organismus nur begrenzt zur Verfügung und kann Strumen in Iodmangelgebieten nicht verhindern. Der Bezug der Uriniodausscheidung auf das Kreatinin liefert nur einen groben Parameter für die tägliche Iodausscheidung und für die Iodbilanzierung.
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  • 47
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    European journal of nutrition 34 (1995), S. 261-268 
    ISSN: 1436-6215
    Keywords: Auswahl von Mahlzeiten ; Einschätzung von Mahlzeiten ; Gesundheitswert ; Entwicklungsstand ; Ernährungserziehung ; Selection of meals ; estimation of meals ; value of health ; age differences ; education of nutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary With regard to the reported knowledge concerning the health value of food in 9–10-year-old children (DGE, 1984) the question arose of whether this knowledge is also valid if pupils have to evaluate meals. Twenty-seven photos of meals (9 each of breakfast, lunch and supper) were presented to 252 children of the age groups 6–7, 9–10 and 12–13 years. By means of these photos, they were requested to organize their meals for 3 days. Subsequent to this procedure the children were asked to evaluate the meals with regard to their health value. The presented meals were classified by five experts of nutrition as more healthy, indifferent and less healthy. The results showed an improved selection of more healthy meals with increasing age. Likewise, the selection of meals for lunch and supper was better than the one for breakfast. There were no differences between boys and girls and children with and without experience of dieting. The evaluation of more healthy and less healthy meals demonstrated an improvement with increasing age. In contradiction to these results, children within all age groups showed a very low level of estimation (10 %) for indifferently classified meals and this level did not improve with increasing age. The results were discussed concerning the establishment of an appropriate education of nutrition with regard to the developmental stage and the emotional and motivational engagement of the children.
    Notes: Zusammenfassung Im Hinblick auf die relativ gute Bewertung einzelner Nahrungsmittel durch 9–10jährige Kinder (DGE, 1984) stellte sich die Frage, ob dieses Wissen gleichfalls für die Einschätzung von Mahlzeiten gilt. 252 Kinder der Altersgruppe 6–7 Jahre, 9–10 Jahre und 12–13 Jahre wurden daher 27 Fotos von Mahlzeiten (je 9mal Frühstück, Mittagessen und Abendbrot) vorgelegt. Die Kinder wurden aufgefordert, ihre Mahlzeiten auf der Basis der vorgelegten Fotos für 3 Tage zusammenzustellen. Danach wurden die Kinder befragt, wie sie die Mahlzeiten bezüglich ihres Gesundheitswertes einschätzen würden. Die vorgelegten Mahlzeiten waren von 5 Experten zuvor als „eher gesund“, „mittelmäßig gesund“ und „eher ungesund“ eingestuff worden. Die Ergebnisse weisen auf eine häufigere Auswahl „eher gesunder“ Mahlzeiten mit ansteigendem Alter hin. Die Auswahl für das Mittagessen und das Abendbrot war unter dem Aspekt des Gesundheitswertes in allen Altersstufen besser als die Auswahl für das Frühstück. Es zeigten sich keine deutlichen Unterschiede zwischen Jungen und Mädchen und Kindern mit und ohne Diäterfahrung. Die Einschätzung der „eher gesunden“ bzw. „eher ungesunden“ Mahlzeiten verbesserte sich gleichfalls mit zunehmendem Alter. Andererseits fand sich bei der Einschätzung der als „mittelmäßig gesund“ eingestuften Mahlzeiten ein recht niedriges Niveau in der richtigen Einschätzung (etwa 10 %) auf allen 3 Altersstufen. Die Ergebnisse werden im Zusammenhang mit gegenwärtigen und künftigen Maßnahmen in der Ernährungserziehung diskutiert, wobei aufgrund der Ergebnisse Entwicklung und Motivation und die emotionalen Bedürfnisse der Kinder stärker zu berücksichtigen sind.
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  • 48
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    European journal of nutrition 34 (1995), S. 166-166 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 49
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    European journal of nutrition 34 (1995), S. 167-176 
    ISSN: 1436-6215
    Keywords: Vitamin C ; Vitamin E ; β-Carotin ; antioxidative Vitamine ; Vitaminaufnahme ; Augenlinse ; Katarakte ; Alter ; Vitamin C ; vitamin E ; β-carotene ; antioxidant vitamins ; vitamin intake ; ocular lens ; cataracts ; elderly
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Senile cataract indicates the opacity of ocular lenses occuring in old and especially in very old people. Lens proteins are extremely long-living and often show oxidative damages. Aging and smoking appear to be the greatest risk factors for the development of lens opacities. The sufficient antioxidant protection of young lenses decreases with the aging process. Consequently, the importance of other protective factors increases. Nutritional factors, particularly vitamins with antioxidant properties, may influence the development of senile cataracts in the ocular lens. Meanwhile an association between the supply with vitamin C, E and β-carotene and the risk of cataract development was demonstrated in animal studies and also in an increasing number of epidemiological studies. These epidemiological studies mainly support the hypothesis that higher vitamin intakes reduce the risk of developing cataracts in old age. The antioxidant properties of the named nutrients give a plausible explanation for the mechanism of cataractogenesis. On the basis of the present data definitive recommendation, necessary for cataract prevention can not yet be established. Some results seem to support higher recommendations. At the moment several large human intervention trials are carried out. Form these studies a further confirmation of the antioxidant hypothesis and of a dose-response-relationship are expected.
    Notes: Zusammenfassung Die senile Katarakt ist eine im Alter und besonders häufig im hohen Alter auftretende Trübung der Augenlinsen. Die extrem langlebigen Linsenproteine weisen häufig oxidationsbedingte Schädigungen auf. Altern und Rauchen erscheinen als die größten Risikofaktoren für eine Kataraktbildung. Während junge Augenlinsen in der Regel über eine ausreichende antioxidative Schutzkapazität verfügen, nimmt diese mit dem Alter ab. Damit wächst die Bedeutung anderer Schutzfaktoren. Nahrungsfaktoren, besonders Vitamine mit antioxidativen Eigenschaften, schützen möglicherweise vor einer Bildung von senilen Katarakten in den Augenlinsen. Ein Zusammenhang zwischen der Versorgung mit Vitamin C, E und β-Carotin und dem Kataraktrisiko konnte in tierexperimentellen Untersuchungen aufgezeigt und inzwischen auch in einer wachsenden Zahl epidemiologischer Studien nachgewiesen werden. Die bisher vorliegenden epidemiologischen Studien unterstützen mehrheitlich die Hypothese, daß erhöhte Vitaminaufnahmen das Risiko einer Kataraktbildung reduzieren. Die antioxidative Wirkung der genannten Nährstoffe liefert eine plausible Erklärung für den Mechanismus der Kataraktgenese. Es fehlen aber noch Studien, aus denen sich die für eine Prävention notwendigen Vitaminmengen ableiten lassen. Einige Untersuchungsergebnisse sprechen möglicherweise dafür, daß diese über den bisher geltenden Empfehlungen liegen. Zur Zeit werden verschiedene, große Interventionsstudien durchgeführt, die eine weitere Absicherung der Antioxidanshypothese und von Dosis-Wirkungsbeziehungen erwarten lassen.
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  • 50
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    European journal of nutrition 34 (1995), S. 240-242 
    ISSN: 1436-6215
    Keywords: Iodine ; iodized salt ; canteen ; lunch meals ; sodium chloride ; Jod ; jodiertes Speisesalz ; Großküche ; Mittagessen ; Natriumchlorid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung In zwei Universitäts-Großküchen, die für die Nahrungszubereitung jodiertes Speisesalz immer (Mensa A) oder nie (Mensa B) verwendeten, wurden 15 möglichst gleiche Mittagessen gesammelt und auf ihre Gehalte an Jodid und NaCl analysiert. Bei durchschnittlich ähnlichem Kochsalzgehalt enthielt das Essen in Mensa A im Mittel 6,1 µg I/100 g ww (8,5 µg I/g NaCl) mehr Jod als in Mensa B. Die Gesamtjodaufnahme mit einem durchschnittlichen Mittagessen in Mensa A betrug demnach 56,5±24,1 µg (Mensa B: 17,0±9,9 µg). Dem Einsatz von jodiertem Speisesalz in der Gemeinschaftsverpflegung scheint somit eine wichtigere Rolle auf dem Weg zu einer ausreichenden Jodaufnahme zuzukommen als bisher angenommen wurde.
    Notes: Summary In each of two university canteens differing in the use (canteen A) or non-use (canteen B) of iodized salt for food preparation, 15 mostly equal lunch meals were collected for iodide and NaCl analysis. With similar NaCl content, the meals of canteen A contained on average 6.1 µg I/100 g ww (8.5 µg I/g NaCl) more I than the meals of canteen B. Total I intake by consumption of an average meal of canteen A was estimated as 56.5±24.1 µg (canteen B: 17.0±9.9 µg). Consequently, the use of iodized salt in central catering seems to play a more important role in a sufficient I intake than assumed so far.
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  • 51
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    European journal of nutrition 34 (1995), S. 284-292 
    ISSN: 1436-6215
    Keywords: Human placenta ; brush border membrane ; alanine transport ; group specific reagents ; SH-groups ; Alanintransport ; menschliche Plazenta ; Kinetik ; gruppenspezifische Reagentien ; SH-Gruppen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Transportsysteme in der apikalen Zellmembran der Syncytiothrophoblasten der Plazenta sind für den Nährstoff-transport aus dem mütterlichen Kreislauf in den fetalen Stoffwechsel von elementarer Bedeutung für Wachstum und Entwicklung des Fötus. Die Carriersysteme für Aminosäuren limitieren dabei die Versorgung des Fötus mit essentiellen und nicht essentiellen Aminosäuren. An isolierten Bürstensaummembranvesikeln (BBMV) reifer menschlicher Placenta haben wir die Aufnahme von neutralen Aminosäuren am Beispiel von Alanin charakterisiert. Darüber hinaus wurden durch den Einsatz gruppenspezifischer Reagentien wichtige Aminosäureseitengruppen der entsprechenden Transportproteine identifiziert. Die Alaninaufnahme in die BBMV wird durch zwei sättigbare Carriersysteme mit unterschiedlichen Eigenschaften vermittelt. Neben einem elektrogenen Na+-abhängigen System, das auch Gln, meAIB und Met transportiert, existiert ein Na+-unabhängiges System, das kein meAIB, dafür aber zusätzlich Leu und Tyr transportiert. Beide Transportsysteme haben gleiche Affinitätskonstanten (Km-Werte) für Alanin (0,45±0,06 mmol/l). Das Na+-abhängige System transportiert Alanin mit einer 1:1 Stöchiometrie mit Na+-Ionen und weist eine 3fach höhere maximale Transportgeschwindigkeit auf. Durch Einsatz gruppenspezifischer Reagentien wurden freie SH-Gruppen in den beiden Carriern identifiziert, die für die Funktion von entscheidender Bedeutung sind. Durch Oxidation und Rückreduktion der SH-Gruppen konnte die Transportleistung der Carrier reversibel verändert werden. Da die modifizierenden Reagentien die SH-Gruppen auch in Gegenwart der Substrate blockierten, ist zu vermuten, daß die wichtigen SH-Gruppen nicht in der Substratbindungsstelle der Transportproteine liegen.
    Notes: Summary We have determined the kinetic characteristics of alanine transport into brush border membrane vesicles (BBMV) of human full term placenta and identified functional groups of the carrier proteins that are important for transport function. Alanine influx into BBMV was found to be mediated by two transport systems with different kinetic features and distinct substrate specificities. An uphill operating electrogenic Na+-dependent contransport system could be kinetically separated from a Na+-independent facilitated diffusion system. The Na+-dependent transporter mediates Na+-alanine cotransport with a 1:1 flux coupling ratio (Hill coefficient 1.13±0.12) and a Km for alanine of 0.45±0.06 mmol/l. Halfmaximal stimulation of Na+-dependent alanine influx was observed at a Na+ concentration (NaCl) of 51.4±1.3 mmol/l. A variety of group specific reagents were used to identify functional groups in the transport proteins. Only compounds reacting with SH-residues (NEM, DTNB, PCMBS) or NH2-groups (PITC) were found to affect Na+ dependent and Na+ independent alanine transport. The EC50 value for inhibition of alanine influx by PCMBS was 450±48 µmol/l. Chemical modifications of SH-groups by PCMBS caused a significant reduction (p〈0.005) in the Vmax for Na+-dependent alanine influx from 0.57±0.06 to 0.16±0.05 nmol·mg protein−1·10s−1 without affecting significantly the Km value. Inhibition by PCMBS was reversed by treatment of BBMV with DTT. When the substrate binding site of the transporter was protected by alanine or leucine, PCMBS still blocked transport function, indicating that the cruical SH groups are not located within the substrate binding site of the transport proteins.
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  • 52
    ISSN: 1436-6215
    Keywords: Sardinen ; Diäten mit Cholesterol bereichert ; Cholesterolspiegel ; Serumtriglyceride ; Olivenöl ; Sonnenblumenöl ; Fried sardines ; cholesterol-enriched diets ; serum cholesterol ; serum triglycerides ; olive oil ; sunflower oil
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The effect of diets containing olive-oil-fried sardines (diet 1) or sunflower-oil-fried sardines (diet 3) upon the serum cholesterolraise induced by dietary cholesterol was studied after a 4-week experiment in growing Wistar rats. Results of diet 1 were compared to those obtained in diets containing casein plus olive oil (diet 2), whereas results of diet 3 were compared to those obtained with casein plus sunflower oil (diet 4). All diets contained cholesterol and bovine bile as a cholesterol-raising agent. The hypercholesterolemic effect of dietary cholesterol in fried-sardine groups (a total cholesterol (TC) increase of 0.9 mmol/L (p〈0.05 and 0.4 mmol/L (not significant) in groups 1 and 3, respectively) was markedly lower than in groups 2 and 4 (a TC increase of 13.9 mmol/L (p〈0.01) and 18.2 mmol/L (p〈0.01), respectively). Serum triglyceride levels decreased in fried-sardine diets (p〈0.05) while they increased in casein diets (p〈0.05). HDL-cholesterol levels appear lower in diet 1 than in diet 2 (p〈0.05), but similar in diets 3 and 4. However, HDL-fraction carries in diets 1, 2, 3 and 4, 13 %, 4 %, 53 % and 5 % of TC, respectively. Results showed that fried-sardine diets exert a powerful check effect on the cholesterol-raising effect induced by dietary cholesterol.
    Notes: Zusammenfassung In Versuchen von 4 Wochen Dauer wurde der Einfluß cholesterolangereicherter Diäten, die in Olivenöl (Diät 1) oder in Sonnenblumenöl (Diät 3) gebratene Sardinen enthielten, auf die Erhöhung des Cholesterolspiegels bei wachsenden Wistar Ratten untersucht. Die Ergebnisse von Diät 1 wurden mit denen von Diät 2 (Kasein plus Olivenöl) und die Resultate von Diät 3 mit denen von Diät 4 (Kasein plus Sonnenblumenöl) verglichen. Alle Diäten enthielten Cholesterol und Rindergalle als cholesterolerhöhende Agentien. Der hypercholesterolämische Effekt war in den Diäten mit den gebratenen Sardinen (eine Erhöhung des Cholesterolspiegels (TC) von je 0.9 mmol/L (p〈0.05) und 0.4 mmol/L (nicht signifikant) in den Gruppen 1 und 3) auffallend kleiner als in den Kontrollgruppen 2 und 4 mit Kasein (eine Erhöhung des TC von je 13.9 mmol/L (p〈0.01) und 18.2 mmol/L (p〈0.05)). Die Serumtriglyceride fielen bei Aufnahme der Sardinen (p〈0.05) und stiegen bei Aufnahme der Kasein-Diäten (p〈0.05). Das HDL-Cholesterolgehalt war niedriger mit Diät 1 als mit Diät 2 (p〈0.05) aber ähnlich bei den Diäten 3 und 4. Die HDL-Fraktion betrug in den Diäten 1, 2, 3 und 4 je 13 %, 4 %, 53 % und 5 % des TC. Diese Ergebnisse zeigen, daß Diäten mit gebratenen Sardinen eine große Hemmwirkung auf den cholesterolerhöhenden Effekt des Cholesterols haben.
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  • 53
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    European journal of nutrition 34 (1995), S. 277-283 
    ISSN: 1436-6215
    Keywords: Selen ; Glutathion-Peroxidase ; Schilddrüsenhormone ; Thyroxin ; Triiodthyronin ; Typ-I-Deiodase ; Selenium ; glutathione peroxidase ; thyroid hormones ; thyroxine ; triiodothyronine ; type-I-deiodinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary In an experiment with 72 male weanling Sprague Dawley rats the effect of varying selenium intake on parameters of thyroid hormone metabolism was investigated. The animals were divided into 6 groups. One of the groups was fed a semi-synthetic diet based on casein which was poor in selenium (38 µg/kg). The other groups were fed the same diet supplemented with Na2SO3·5H2O to achieve a selenium concentration of 50, 100, 300, 600 and 3 000 µg/kg. The experiment lasted 40 days. Different selenium intake had no effect on food intake, weight gain, hematological and selected clinical-chemical parameters. Determination of glutathione peroxidase activity and selenium concentration of serum showed a selenium deficiency in animals fed the diet not supplemented with selenium. Serum T3 concentration and hepatic type-I-deiodinase activity were decreased in the group without selenium supplementation in contrast to the groups fed diets adequate in selenium (100, 300 µg/kg). A diet supplementation of 50 µg/kg already increased hepatic type-I-deiodinase activity to levels of the groups fed diets adequate in selenium. In groups supplemented with 600 and 3 000 µg/kg diet, serum T3 concentration was reduced by half of groups fed diets adequate in selenium. Supplementation with 3 000 µg Se/kg lowered the type-I-deiodinase activity in contrast to groups fed diets adequate in selenium, but not significantly. Serum concentrations of T4 and fT4 were not changed by various selenium intake. The results of this investigation show an alteration in thyroid hormone metabolism at low selenium intake as well as at high selenium intake.
    Notes: Zusammenfassung Die Auswirkungen einer unterschiedlichen Selenversorgung auf Parameter des Stoffwechsels der Schilddrüsenhormone sollten in einem Versuch mit 72 männlichen wachsenden Sprague Dawley Ratten untersucht werden. Die Tiere wurden in 6 Gruppen eingeteilt, wovon eine Gruppe eine selenarme halbsynthetische Diät auf Caseinbasis mit einem Se-Gehalt von 38 µg/kg erhielt. Die übrigen Gruppen erhielten die selbe Diät, die durch Zulage von Na2SO3·5H2O auf Selengehalte von 50, 100, 300, 600 und 3 000 µg/kg gebracht wurde. Die Versuchsdauer betrug 40 Tage. Die unterschiedliche Zufuhr von Selen hatte keinen Einfluß auf Futteraufnahme, Entwicklung der Lebendmasse, hämatologische und ausgewählte klinisch-chemische Parameter. Ein Selenmangel bei der Gruppe, die die nicht supplementierte Basisdiät erhalten hatte, konnte anhand der Aktivität der Glutathion-Peroxidase und der Selenkonzentration im Serum diagnostiziert werden. Beide Parameter stiegen ab einer Se-Zulage von 300 µg/kg noch an, allerdings geringfügig. Die Konzentration von T3 im Serum und die Aktivität der Typ-I-Deiodase in der Leber der Gruppe ohne Selenzulage war im Vergleich zu den bedarfsgerecht (100, 300 µg/kg) versorgten Gruppen vermindert. Bereits eine Selenzulage von 50 µg/kg Diät konnte die Aktivität der Typ-I-Deiodase auf die Werte der bedarfsgerecht versorgten Gruppen mit 100 und 300 µg Selenzulage anheben. Bei den Gruppen mit 600 und 3 000 µg/kg Diät Selenzulage war die Konzentration von T3 im Serum im Vergleich zu den bedarfsgerecht versorgten Gruppen auf etwa die Hälfte reduziert. Durch die Selenzulage von 3 000 µg/kg Diät war die Aktivität der Typ-I-Deiodase gegenüber den bedarfsgerecht versorgten Gruppen vermindert, die Verminderung war jedoch nicht statistisch signifikant. Die Konzentrationen von T4 und fT4 waren durch die unterschiedliche Selenzufuhr kaum verändert. Die Untersuchung zeigt insgesamt, daß sowohl unzureichende als auch über den Bedarf hinausgehende Selenzufuhr zu Veränderungen im Stoffwechsel der Schilddrüsenhormone führt.
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    European journal of nutrition 34 (1995), S. 1-1 
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    Source: Springer Online Journal Archives 1860-2000
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    European journal of nutrition 34 (1995), S. 30-31 
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    Source: Springer Online Journal Archives 1860-2000
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  • 56
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    European journal of nutrition 34 (1995), S. 113-117 
    ISSN: 1436-6215
    Keywords: Blei ; Cadmium ; Quecksilber ; Gewürze ; Gewürzzubereitungen ; Wurstwaren ; Lead ; cadmium ; mercury ; spices ; condiments ; meat products
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary The lead and cadmium contents of 50 spices and 19 condiments were investigated by means of flameless atomic absorption spectrophotometry. Mercury contents were determined by cold vapor atomic absorption method including amalgamation. The mean concentrations of lead, cadmium, and mercury were 0.470 mg/kg, 0.080 mg/kg, and 0.005 mg/kg, respectively. By using the detected levels of these three heavy metals in model calculations only a small carry-over of lead, cadmium, and mercury in meat products by spices and condiments can be assumed.
    Notes: Zusammenfassung 50 Gewürze und 19 Gewürzzubereitungen wurden mittels flammenloser Atomabsorptionsspektrometrie auf ihren Blei- und Cadmiumgehalt sowie mittels Kaltdampftechnik und nachfolgender Amalgamierung auf ihren Quecksilbergehalt untersucht. Im Mittel wurden hierbei 0,470 mg Blei, 0,080 mg Cadmium und 0,005 mg Quecksilber pro kg Würzmittel gefunden. Anhand von Modellrechnungen wurde ein nur geringer Blei-, Cadmium- und Quecksilbereintrag über Würzmittel in die Wurstsorten Fleischwurst, Leberwurst und Mettwurst aufgezeigt.
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  • 57
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    European journal of nutrition 34 (1995), S. 137-142 
    ISSN: 1436-6215
    Keywords: Taurine ; plasma ; whole blood ; depletion ; supplementation ; Taurin ; Plasma ; Gesamtblut ; Taurinmangel ; Supplementation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Die vorliegende Studie untersuchte die Beziehung zwischen der Taurinkonzentration in Plasma und Gesamtblut unter normalen physiologischen Bedingungen bei Menschen und bei Katzen sowie nach oraler Taurinsupplementierung beim Menschen und nach taurinfreier Fütterung bei Katzen. Beim Menschen betrug die durchschnittliche Taurinkonzentration im Plasma 44±8 µmol/L und im Gesamtblut 222±35 µmol/L. Unter diesen „physiologisch normalen“ Bedingungen bestand zwischen der Taurinkonzentration in Plasma und Gesamtblut keine Korrelation (r=0.092). Die Plasmataurinkonzentration stieg nach oraler Taurinsupplementierung beim Menschen rasch an bzw. fiel schnell nach taurinfreier Ernährung bei Katzen ab. Die Taurinkonzentration im Gesamtblut war dagegen mehr inert und änderte sich erst nach anhaltender Taurinzufuhr beim Menschen bzw. nach andauerndem Taurinmangel bei Katzen.
    Notes: Summary In the present study the relationship between plasma and whole blood taurine was examined under normal physiological circumstances in humans and cats. In addition, the effect of taurine supplementation on plasma and whole blood taurine was evaluated in humans and the depletion of taurine pools after a taurine-deprived diet was studied in cats. The normal plasma taurine concentration in humans was 44±8 µmol/L and the whole blood taurine concentration was 227±35 µmol/L. Under normal physiological conditions plasma and whole blood taurine were not correlated (r=0.092). Plasma taurine responded rapidly to dietary supplementation in humans or the taurine depletion in cats. In contrast, the whole blood taurine pool was more inert and varied only under extremes of depletion (cats) or sustained taurine supplementation.
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  • 58
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    Keywords: Strontium ; oraler Strontium-Test ; Calcium ; Absorption ; gesunde Probanden ; Strontium ; oral strontium test ; calcium ; absorption ; healthy volunteers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Intestinal strontium absorption has been discussed recently as an indirect measure for calcium uptake. Prerequisite for the clinical use of an oral strontium test is the availability of a reliable procedure including controlled strontium supply, sample pretreatment and analysis as well as the assessment of normal values. In the present study, a group of young females (n=33; 24.0 ± 2.7 y; BMI 21.5 ± 1.9) received an oral dose of 2.27 mmol strontium in a standardized breakfast that contained 0.625 mmol calcium. Before and 220 min after the bolus serum strontium concentrations were determined by means of atomic absorption spectrophotometry (coefficient of variation: within day 4.8 %, n=10; day-to-day 9.5 %, n=8). The error of the method was 2.7 %. Calculation of the fractional strontium absorption rate considered the respective distribution volume (extracellular fluid; either estimated using body weight or determined by means of bioimpedance analysis [BIA]). Average absorption rates were 13.3 ± 3.1 % and, considering BIA measurement 13.6 ± 2.6 %, respectively. Smoking, exercise and, use of oral contraceptives showed no effects. Our oral strontium test is characterized by excellent reliability, easy handling and low costs and, thus, is suitable for routine use.
    Notes: Zusammenfassung Die Erfassung der Strontiumabsorption wird heute als indirektes Verfahren zur Beurteilung der intestinalen Calciumabsorption diskutiert. Voraussetzung für die klinische Anwendung ist ein vertrauenswürdiges Testverfahren inclusive kontrollierter Strontiumgabe, Probenaufarbeitung und -analyse sowie die Erfassung von Normalwerten. Für unsere Studien wurde ein Kollektiv junger Frauen (n=33, 24,0 ± 2,7 Jahre; BMI 21,5 ± 1,9) herangezogen. Die Probandinnen erhielten eine Bolusgabe von 2,27 mmol Strontium zusammen mit einem Standardfrühstück (ca. 0,625 mmol Calcium). Vor und 220 min nach der Bolusgabe erfolgte die Bestimmung des Serum-Strontiumgehaltes mittels Atomabsorptionsspektrometrie. Der Variationskoeffizient der Methode lag innerhalb eines Tages bei 4,8 % (n=10) und von Tag zu Tag 9,5 % (n=8). Der Fehler der Methode betrug 2,7 %. Die Berechnung der fraktionellen Strontiumabsorptionsrate erfolgte unter Berücksichtigung des entsprechenden Verteilungsraumes (Extrazellulärflüssigkeit; Schätzverfahren über Körpergewicht bzw. Bioimpedanz-Analyse [BIA]). Die Strontiumabsorptionsrate lag im Mittel bei 13,3 ± 3,1 %, unter Berücksichtigung der BIA-Werte bei 13,6 ± 2,6 %. Rauchen, sportliche Aktivität bzw. Einnahme oraler Kontrazeptiva zeigten keinen Einfluß. Das hier vorgestellte Testverfahren ist aufgrund seiner hohen Vertrauenswürdigkeit und relativ einfacher Handhabung für Routine-untersuchungen geeignet.
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  • 59
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    European journal of nutrition 34 (1995), S. 214-219 
    ISSN: 1436-6215
    Keywords: Amylin ; food intake ; vagotomy ; circadian effect ; rat ; Amylin ; Futteraufnahme ; Vagotomie ; zirkadiane Effekte ; Ratte
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Das aus dem Pankreas stammende Peptid Amylin (1 µg/kg) reduzierte nach intraperitonealer (IP) Injektion die kumulative Futteraufnahme bei Ratten, denen vor der Injektion das Futter für 24 h entzogen worden war bzw. bei Ratten, denen Futter ad lib. zur Verfügung stand, für bis zu 4 h. Der Effekt trat zu verschiedenen Zeitpunkten des Tag/Nacht-Zyklus (Beginn der Dunkelphase, Mitte der Dunkelphase, Beginn der Hellphase) auf. Der verzehrsreduzierende Effekt von IP verabreichtem Amylin wurde zu keinem dieser Zeitpunkte durch subdiaphragmatische Vagotomie aufgehoben. Vagotomie führte eher zu einer Verstärkung des verzehrsreduzierenden Effekts von Amylin, und zwar nach einem 24stündigen Futterentzug bei Injektion zu Beginn der Hellphase oder in der Mitte der Dunkelphase. Im Unterschied zu früheren Untersuchungen mit älteren Ratten konnte ein verzehrsreduzierender Effekt von Amylin auch bei Ratten beobachtet werden, denen vor der Injektion das Futter nicht entzogen worden war. In Ergänzung früherer Befunde zeigen also die Ergebnisse, daß der verzehrsreduzierende Effekt von IP verabreichtem Amylin zu verschiedenen Tageszeiten ausgelöst und durch subdiaphragmatische Vagotomie nicht aufgehoben werden kann.
    Notes: Summary The pancreatic peptide amylin (1 µg/kg) injected intraperitoneally reduced cumulative food intake for up to 4 h in food-deprived (24 h) and non-deprived rats at various times of the day, i.e., at dark onset, in the middle of the dark phase, and at light onset. At none of these times did subdiaphragmatic vagotomy abolish the anorectic effect of amylin. Rather, vagotomy enhanced, by unknown mechanisms, amylin's anorectic effect in food-deprived rats at light onset and in the middle of the dark phase. In contrast to previous studies with older rats, amylin's anorectic effect was also observed when injected into nondeprived rats. The findings of the present study extend previous reports in that amylin's anorectic effect, not being abolished by abdominal vagotomy after intraperitoneal injection, can be elicited at different times of the day.
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    European journal of nutrition 34 (1995), S. 236-239 
    ISSN: 1436-6215
    Keywords: Verpflegungsplanung ; Krankenhausverpflegung ; Diabetesdiät ; Speisenauswahl ; wissensbasiertes System ; Menu planning ; hospital menu ; diabetes diet ; food selection ; knowledge-based system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Menu planning in hospitals is a complex decision problem. Patients expect the menu plan to be healthful and in accordance with their nutritional habits. Furthermore, the menu plan must conform to capacity limits of the kitchen. In this paper we present an approach to computerized food selection and menu composition. The model is based on nutritional knowledge, which is represented in the computer and used for problem solving.
    Notes: Zusammenfassung Die Planung einer Krankenhausverpflegung stellt sich als komplexes Entscheidungsproblem dar. Die Verpflegung soll der Gesundheit der Patienten zuträglich sein, deren Ernährungsgewohnheiten entsprechen und im Rahmen der Küchenkapazität hergestellt werden können. In der vorliegenden Arbeit wird am Beispiel der Diätverpflegung für Diabetiker ein computerunterstütztes Modell vorgestellt, das den Entscheidungsträgern im Krankenhaus Hilfestellung bei der Auswahl der Speisen und deren Zusammenstellung zu Menüs bietet. Die Planung erfolgt auf der Basis ernährungs- und haushaltswissenschaftlichen Fachwissens, das im Computer abgebildet und zur Problemlösung genutzt wird.
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    European journal of nutrition 34 (1995), S. 32-33 
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    Source: Springer Online Journal Archives 1860-2000
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  • 62
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    European journal of nutrition 34 (1995), S. 34-34 
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    European journal of nutrition 34 (1995), S. 95-112 
    ISSN: 1436-6215
    Keywords: Ernährungsgeschichte ; Nahrungsgewohnheiten ; Ernährungspolitk ; Lebensmittelverfälschungen ; Lebensmittelrecht ; Food history ; food habits ; food policy ; food adulterations ; food legislation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary During the last two decades, there has been an increasing movement in Germany to protect the natural environment from dangerous substances. This has renewed a growing common interest in government food control. This contribution ask the question of how this food legislation as a part of the general food and health policy in Germany came into being, and which promoting as well as inhibiting determinants in this scope could be observed. These statements are based partly on results of a project of the German National Research Council (Deutsche Forschungsgemeinschaft) in which the author investigates the change of food habits under the impact of industrialization and urbanization since the last century in a larger historical perspective and in a quantitative and qualitative manner with the help of current sources.
    Notes: Zusammenfassung Die in den letzten beiden Jahrzehnten in Deutschland angewachsene Bewegung zum Schutz der natürlichen Ressourcen und der verstärkten Reinerhaltung der Umwelt vor gefährlichen Schadstoffen hat auch die staatliche Lebensmittelüberwachung wieder stärker in den Brennpunkt des öffentlichen Interesses gerückt. Der Beitrag geht der bisher nur unzureichend behandelten Frage nach, wie diese gesetzliche Lebensmittelkontrolle als Bestandteil staatlicher Ernährungs- und Gesundheitspolitik in Deutschland entstanden ist und welche beschleunigenden und hemmenden Determinanten es dabei gegeben hat. Die Ausführungen basieren auf Teilergebnissen eines neuen Projekts der Deutschen Forschungsgemeinschaft, mit dem der Verfasser den Wandel der Nahrungsgewohnheiten unter dem Einfluß der Industrialisierung und Urbanisierung seit dem vorigen Jahrhundert erstmals im größeren historischen Zusammenhang anhand der überlieferten zeitgenössischen Quellen quantitativ wie qualitativ analysiert.
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    European journal of nutrition 34 (1995), S. 151-159 
    ISSN: 1436-6215
    Keywords: Fischöl ; Hyperlipoproteinämie ; Omega-3-Fettsäuren ; Triglyzeride ; Vitamin E ; Fish oil ; hyperlipoproteinemia ; omega-3 fatty acids ; triglycerides ; vitamin E
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary In 56 patients with HLP (40 with hypertriglyceridemia and mixed HLP respectively and 16 with hypercholesterolemia), changes in the lipid state and in the parameters of the antioxidative potential before and after a 4-week olive-oil phase, and after 8-, 20-and 32-week intakes of salmon-oil capsules were determined. The treatment with salmon-oil led to a decrease of triglycerides in patients with hypertriglyceridemia and mixed HLP respectively, on the other hand, it led to an increase of cholesterol in hypercholesterolemia. The increase of malondialdehyde as measure of lipid peroxidation in both patient groups underlines the necessity of a substitution of antioxidants. Further investigations are necessary before wide use of fishoil capsules can be recommended, expecially to avoid side-effects.
    Notes: Zusammenfassung Bei 56 Patienten mit HLP (40 Hypertriglyzeridämie bzw. mixed HLP und 16 mit Hypercholesterinämie) wurden Veränderungen im Lipidstatus und bei Parametern des antioxidativen Potentials vor und nach einer vierwöchigen Olivenölphase und nach 8, 20 und 32 Wochen Einnahme von Lachsölkapseln ermittelt. Die Behandlung mit Lachsöl führte bei Patienten mit Hypertriglyzeridämie/mixed HLP zu einer Senkung der Triglyzeride, dagegen bei Hypercholesterinämie zu einer Zunahme des Cholesterins. Die Erhöhung des Malondialdehyds als Maß für die Lipidperoxidation in beiden Patientengruppen unterstreicht die Notwendigkeit einer Substitution mit Antioxidantien. Vor einem breiten Einsatz von Fischölkapseln sind allerdings weitere Untersuchungen, nicht zuletzt zur Verringerung der Nebenwirkungen, erforderlich.
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    European journal of nutrition 34 (1995), S. 143-150 
    ISSN: 1436-6215
    Keywords: Fischöl ; Olivenöl ; Sauen ; Energiebilanz ; Thermogenese ; Gaswechsel ; Fish oil ; olive oil ; sows ; energy balance ; thermogenesis ; gaseous exchange
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary An animal model experiment was conducted with nine adult sows to study the effect of olive oil and fish oil (40 % polyunsaturated fatty acids) on thermogenesis compared to wheat starch as control. The treatments were given to each animal according to a latin square design. The basal diet (20 g DM/kg W0.75) was mainly based on barley and soybean meal, and matched 60 % of the ME requirements with all the other nutrients meeting maintenance requirements. The isoenergetic supplements amounted to 176 kJ gross energy per kg W0.75 and day. During each experimental period a complete energy balance was recorded for each animal using indirect calorimetry technique (RQ-method) as well as the carbonnitrogen-balance technique. The treatments did not influence the digestibility of the rations. Digestibility of energy and of carbon averaged 83.4 % and 83.3 %, respectively. All three supplements were nearly completly digested as calculated by the difference method. Fish oil increased urine energy and decreased CH4 production, the shifts, however, were in absolute terms very small. The mean O2 consumption was 1 002 l/d showing no significant treatment effects. CO2 production was lowered with olive oil by 10 %, and with fish oil by 13 % compared to the starch diet. The daily heat production was 20.95, 20.72, and 20.04 MJ when starch, olive oil or fish oil was given. Corrected for equal energy retention the difference of thermogenesis between olive oil and starch was −0.4 MJ/d, and between fish oil and starch −1.2 MJ/d. These differences corresponded to a relation of starch:olive oil:fish oil=1:0.95:0.86. The relation between starch and olive oil reflected exactly the theoretical expectation, calculated from the ATP regeneration by oxidation of both nutrients. When fish oil was added, the daily heat production was lower than theoretically calculated, which might be interpreted as an effect on the metabolic rate in general rather than especially on the efficiency of ATP formation from fish oil oxidation. In any case, there was no hint of a facultative thermogenesis induced by the oils.
    Notes: Zusammenfassung Mit Hilfe der kalorimetrischen Bilanztechnik wurde an 9 Sauen nach dem Schema eines lateinischen Quadrates die Wirkung von Olivenöl und Fischöl im Vergleich zu Weizenquellstärke auf die Thermogenese im Erhaltungsstoffwechsel gemessen. Die zu prüfenden Nährstoffe wurden einer Basisration (20 g TM/kg W0,75) zugelegt, die auf 60 % des energetischen Erhaltungsbedarfs an umsetzbarer Energie ausgerichtet war. Die isoenergetischen Zulagen betrugen jeweils 176 kJ Bruttoenergie/kg W0,75. Von allen Tieren wurde in jeder Stoffwechselperiode eine vollständige Energiebilanz erfaßt. Die Versuchsbehandlung hatte keinen Einfluß auf die Verdaulichkeit der Rationen. Die mittleren VQ-Werte der Gesamtration betrugen 83,4 % für Energie und 83,3 % für Kohlenstoff. Die Energieverdaulichkeit der Zulagen betrug in allen Fällen um 100 %. Fischöl erhöhte signifikant die Harnenergie und verminderte die CH4-Bildung im Vergleich zu den beiden anderen Rationen. Allerdings waren diese Veränderungen absolut gesehen nur minimal. Der Sauerstoffverbrauch betrug im Mittel 1002 l/d und zeigte keine Behandlungsdifferenzen. Die CO2-Abgabe war bei Verabreichung von Olivenöl um 10 % und bei Fischöl um 13 % signifikant niedriger. Die tägliche Wärmebildung betrug 20,95, 20,72 bzw. 20,04 MJ bei Fütterung der Rationen mit Stärke, Olivenöl bzw. Fischöl. Auf der Basis gleicher Energieretention verglichen, betrug der Unterschied in der Thermogenese zwischen Olivenöldiät und Stärkediät −0,4 MJ/d, der zwischen Fischöldiät und Stärkediät −1,2 MJ/d. Dies entsprach einer Relation von Stärke:Olivenöl:Fischöl=1:0,95:0,86. Das Verhältnis zwischen Stärke:Olivenöl widerspiegelte genau die theoretische Erwartung aufgrund der ATP-Regenerierung durch Oxidation dieser beiden Nährstoffe. Fischöl (ca. 40 % mehrfach ungesättigte Fettsäuren) wies eine tendenziell niedrigere Thermogenese als theoretisch erwartet auf, was möglicherweise auf einer entsprechenden Absenkung des Erhaltungsumsatzes beruhte. Die Ergebnisse zeigen, daß die verwendeten Öle keine fakultative Thermogenese induzierten.
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    European journal of nutrition 34 (1995), S. 183-189 
    ISSN: 1436-6215
    Keywords: Validation ; 24-hour recall questionnaire ; dietary survey ; energy intake ; nutrient intake ; food intake ; Validierung ; 24-hour-recall-Fragebogen ; Ernährungserhebung ; Energieaufnahme ; Nährstoffaufnahme ; Nahrungsaufnahme
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Ziel der Arbeit war, die relative Validität eines selbstgeführten 24-hour-recall-Fragebogens zu untersuchen, der in einer Ernährungserhebung mit 3 653 weiblichen und männlichen Erhebungsteilnehmern im Alter ab 7 Jahren eingesetzt wurde. Die Validierung wurde an einer Gruppe von 41 Männern durchgeführt. Ein 3-Tage-Protokoll diente als Referenzmethode. Der Vergleich des 24-hour-recall-Fragebogens mit dem 3-Tage-Protokoll erbrachte gute Übereinstimmung. Mittels des Wilcoxon matched-pairs ranked signs test (p〈0.05) konnten nur für die absoluten Energie- und Kohlenhydrataufnahmen sowie für die Protein-Nährstoffdichte signifikante Unterschiede nachgewiesen werden. Die prozentuale Verteilung der Energie auf die Hauptnährstoffe und Alkohol differierte um maximal 2,4 %. Der mediane prozentuale Unterschied in der absoluten Nährstoffaufnahme und der Nährstoffdichte lag zwischen −9 und 22 %. Die tägliche Nahrungsaufnahme war nur für 3 von 10 Lebensmittelgruppen signifikant verschieden. Die Spearman rank Korrelationskoeffizienten betrugen für alle Nährstoffdichten mehr als 0,35. Die höchsten Korrelationskoeffizienten um 0,60 wurden für die Alkoholund Nahrungsfaseraufnahme beobachtet. Die Ergebnisse zeigen, daß der 24-hour-recall-Fragebogen eine valide Methode zur Schätzung der medianen und mittleren Nahrungs-und Nährstoffaufnahme von großen Gruppen ist.
    Notes: Summary This study investigated the relative validity of a self-administered 24-h recall questionnaire in a dietary survey on 3 653 men and women 7 years of age and older. The validation was carried out in a group of 41 men. An estimated dietary record kept over 3 days served as reference method. Comparison of the questionnaire and the estimated 3-day record showed good agreement. The Wilcoxon matchedpairs ranked signs test (p〈0.05) demonstrated that the only differences were the crude energy and carbohydrate intake and the estimated nutrient density of protein. The estimated proportion of calories from carbohydrate, fat, protein, and alcohol differed by no more than 2.4 %. The median percentage differences in crude nutrient intakes and nutrient densities between the two assessment techniques ranged from −9 % to 22 %. The daily food intake differed significantly in only three of ten food groups. Spearman's correlation coefficients were higher than 0,35 for all density measurements. The highest correlation coefficients of about 0.60 were observed for alcohol and dietary fiber intake. It is concluded that the self-administered 24-hour recall questionnaire is a valid method for estimating the median and mean dietary intake of large groups of subjects.
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  • 67
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    European journal of nutrition 34 (1995), S. 198-205 
    ISSN: 1436-6215
    Keywords: Forelle ; Tocopherol ; Phyllochinon ; Antioxidans ; Lipidstabilität ; Trout ; tocopherol ; phylloquinone ; antioxidant ; storage
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Rainbow trouts were fed a complete diet with 12 mg vitamin K3 and supplemented with 20, 200 or 2 000 mg all-rac-α-tocopheryl-acetate/kg for 18 weeks. The ratio of the vitamin E-supplementation was 1 : 10 : 100. Fillets were minced and stored at −18 °C. Concentrations of α-tocopherol and phylloquinone and parameters of lipid peroxidation were measured after 4, 6, and 8 months of storage. The effects of α-tocopherol incorporated into fillets on storage stability were assessed by measuring free fatty acids, peroxides, malondialdehyde and lipofuscin. Mean α-tocopherol-concentrations in fillets were 1.4, 2.7 and 16.3 mg/100 g, respectively representing ratios of 1 : 2 : 12. The increase in α-tocopherol concentration resulted in a significant improvement of storage stability. The phylloquinone concentration in fillet was reduced in treatments with ≥200 mg vitamin E/kg; however, this did not affect the prothrombin time. No peroxides were detectable at any time. The concentrations of malondialdehyde significantly decreased with increasing supplementation of vitamin E. Lipofuscin concentrations were higher with low than with high vitamin E supplementation. The dose-related inhibition of lipid peroxidation became apparent in decreased concentrations of the free fatty acids in the crude fat. These results confirm the effectiveness of α-tocopherol as antioxidant in fish flesh. In this study the incorporation of α-tocopherol from dietary supplementation improved the long-term storage quality of trout fillets due to the effective inhibition of the lipid peroxidation. A measurable improvement of the storage stability was achieved with a supplementation of 200 mg vitamin E/kg feed.
    Notes: Zusammenfassung Filet von Forellen, die 18 Wochen lang ein Futter mit 12 mg Menadion/kg und mit drei im Konzentrationsverhältnis von 1 : 10 : 100 gestaffelten Dosierungen von all-rac-α-Tocopherylacetat (20, 200 und 2 000 mg/kg) erhalten hatten, wurde homogenisiert und bei −18 °C gelagert. Nach Lagerung über 4, 6 und 8 Monaten wurden die Konzentrationen an α-Tocopherol und Phyllochinon sowie von freien Fettsäuren, Peroxiden, Malondialdehyd und Lipofuszin als Parameter der Lipidperoxidation analysiert. Die mittleren α-Tocopherolgehalte betrugen 1,4; 2,7 und 16,3 mg/100 g Filet, entsprechend einem Konzentrationsverhältnis von etwa 1 : 2 : 12. Der dosisabhängige Anstieg bewirkte eine deutliche Verbesserung der Lagerstabilität. Die hohen Dosen an Vitamin E führten zu abnehmenden Gehalten an Phyllochinon im Fischmuskel, die ohne Einfluß auf die Prothrombinzeit waren. Die dosisabhängige Hemmung der enzymatisch katalysierten Fettoxidation spiegelte sich in abfallenden Gehalten an freien Fettsäuren im Rohfett wider. Peroxide waren an keinem Untersuchungstermin nachweisbar. Die Gehalte an Malondialdehyd sanken mit zunehmender Supplementierung von Vitamin E signifikant ab. Derselbe Einfluß zeigte sich bei Lipofuszin. Die Anreicherung der Filets mit α-Tocopherol nach Supplementierung des Futters begünstigte eine längerfristige Qualität bei Gefrierlagerung infolge einer effektiven Hemmung der Lipidperoxidation. Bereits mit der Dosierung von 200 mg α-Tocopherylacetat/kg Futter konnte im Vergleich zur Dosierung von 20 mg/kg eine meßbare Verbesserung der Lagerstabilität erzielt werden.
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  • 68
    ISSN: 1436-6215
    Keywords: ω-3 Fettsäuren ; Kolonkarzinom ; Diät ; Fett ; Lipoproteine ; ω-3 fatty acids ; colonic neoplasms ; diet ; fat ; lipoproteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Summary Several studies indicated a protective effect of fish oil on colon carcionogenesis which might be due to alterations in prostaglandin E2 synthesis of the colonic mucosa. Additional effects on fecal bile acid excretion may also play a role since especially secondary bile acids are known to act as promotors in colon cancer development. In the present study possible influences on bile acid excretion were investigated in 12 healthy volunteers whose daily diet was supplemented for 4 weeks with 11 g of fish oil (FO) and corn oil (CO) per day, respectively. Fecal bile acids were analyzed by gas-liquid-chromatography. Fecal excretion of total bile acids was not different during the periods of FO and CO-supplementation (301.9 vs. 320.3 mg/day). However, a non-significant trend to a lower daily excretion of the secondary bile acid lithocholic acid was found after FO compared to CO-ingestion (99.6 vs. 109.4 mg/day; p=0.22). Since secondary bile acids are known promotors of colon carcinogenesis, these findings may implicate a favorable situation with respect to colon cancer prevention.
    Notes: Zusammenfassung Verschiedene Studien weisen auf einen protektiven Effekt von Fischöl bei der Kolonkarzinomentstehung hin. Mögliche Einflüsse auf die muscosale Prostaglandin-E2-Synthese wurden hierbei als Wirkungsmechanismus beschrieben. Zusätzliche Effekte auf die fäkale Exkretion von Gallensäuren könnten ebenso von Bedeutung sein, da insbesondere sekundäre Gallensäuren als Promotoren bei der Kolontumorentstehung angesehen werden. In der vorliegenden Studie wurde bei 12 gesunden Probanden der Effekt einer täglichen Supplementierung mit 11 g Fischöl (FO) bzw. Maiskeimöl (MO) über jeweils 4 Wochen zusätzlich zu einer fettreduzierten Basiskost (30 % der Gesamtenergie als Fett) auf die fäkale Exkretion von Gallensäuren untersucht. Die Analyse des fäkalen Gallensäurenspektrums erfolgte gaschromatographisch. Die Gesamtausscheidung an Gallensäuren war unter FO nicht signifikant verschieden von derjenigen unter MO (301,9 vs. 320,3 mg/Tag). Unter FO ergab sich jedoch eine tendenziell niedrigere Exkretion der sekundären Gallensäure Lithocholsäure als unter MO (99,6 vs. 109,4 mg/Tag, p=0,22). Da sekundäre Gallensäuren als ein wesentlicher Promotor der Kolonkarzinogenese angesehen werden, sind diese Veränderungen positiv im Hinblick auf eine mögliche Kolonkarzinomprävention zu werten.
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    European journal of nutrition 34 (1995), S. 243-244 
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    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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    European journal of nutrition 34 (1995), S. 245-251 
    ISSN: 1436-6215
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
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  • 71
    ISSN: 1436-6215
    Keywords: Deep-fat frying ; sunflower oil ; column and HPSE chromatographies ; color index ; acid value ; UV absorption ; Ölbad-Fritierung ; Sonnenblumenöl ; Säulen- und HPSE-Chromatographie ; Farbindex ; Säurezahl ; Refraktionsindex ; UV-Absorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung Chemische und physikalische Standardkennzahlen, wie zum Beispiel der Refraktions-und Farbindex, die Säurezahl und der K270-Wert, wurden mit den Gehalten an polaren Verbindungen sowie spezifischen thermooxidativen und hydrolytischen Fettbestandteilen verglichen, die in einem Sonnenblumenöl, das 75 mal zum Fritieren von Kartoffeln benutzt worden war, entstanden sind. Der Farbindex, die Säurezahl, der K270-Wert und der Gehalt an polaren Verbindungen stiegen signifikant (p〈0,05) nach 30 Fritierungen. Anschließend stabilisierten sich die drei letztgenannten Indices. Der Inhalt an polymeren Verbindungen und Triglyceridendimeren stieg signifikant nach 30 Fritierungen an (p〈0,05), während die oxidierten Triglyceride keine signifikante Steigerung aufwiesen. Der Gehalt an Diglyceriden und freien Fettsäuren, als Maß der hydrolytischen Vorgänge, zeigte während des Fritierprozesses keine signifikante Veränderung. Die signifikanten Korrelationen zwischen der Säurezahl und dem Gehalt an polaren Verbindungen, den dimeren und polymeren Triglyceriden und den oxydierten Triglyceriden, zwischen dem Farbindex und dem Gehalt an polaren Verbindungen und polymeren Triglyceriden, oder zwischen dem K270-Wert und den polymeren Triglyceriden zeigen, daß diese einfachen Standard-Methoden benutzt werden können und genauso nützlich sind wie mehr spezifische Methoden zur Bewertung von Fritierprozessen, wenn man die Ausgangswerte aller dieser Indices kennt.
    Notes: Summary Standard chemical and physical indexes, such as color index, acid value, and K270 were compared with the polar content and the specific thermoxidative and hydrolytic compounds originated during 75 potato fryings with sun-flower oil. The color index, acid value, K270 and total polar content showed a significant increase (p〈0.05) after the first 30 fryings, followed by a tendency of the last three indexes to reach a near-steady state. Triglyceride polymers and triglyceride dimers showed a significant increase (p〈0.05) after 30 fryings, while the oxidized triglycerides were not increased significantly after 30 fryings. The amount of diglycerides and free fatty acids related to hydrolytic alteration did not change significantly throughout the frying operations. The significant correlations between acid value and total polar content, triglyceride dimers, triglycerides polymers and oxidized triglycerides, or between color index and polar content and triglyceride polymers or between K270 and triglyceride polymers indicate that these simple and standard methods can be applied and they are as useful as more specific methods of evaluation in the monitoring of frying operations, provided that initial values of all of these indexes are available.
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    Lasers in medical science 10 (1995), S. 37-42 
    ISSN: 1435-604X
    Keywords: Enamel ; Etch ; Laser ; Acid ; Nd-YAG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Acid etching is regarded as one of the main means of providing additional retention in aesthetic dentistry. Alternative methods of achieving bonding to tooth tissue which have been proposed include laser etching. Conflicting results on bond strength to enamel have been reported for laser etching. Here the tensile bond strength of composite resin to acid- and laser-etched enamel was measured and the topographical differences between the surfaces were evaluated using the scanning electron microscope. The laser used was a pulsed Nd-YAG laser at 10 pulses per second with a pulse length of 150μs, 80mJ pulse−1, 1.064μm wavelength. The results obtained indicate that the bond strength of laser-etched enamel was significantly lower than that of acid-etched enamel. In this study the difference may be attributable to the chromophore used. Variations in the rate of traverse of the laser tip across the surface did not appear to produce significant alterations in the bond strength.
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  • 73
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    Lasers in medical science 10 (1995), S. 31-36 
    ISSN: 1435-604X
    Keywords: Embryonal carcinoma ; F9 cells ; Laser ; Hyperthermia ; Nigericin ; Acidosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract The aim of this study was to investigate how acidosis affects the sensitivity of F9 embryonal carcinoma cells to conventionally induced hyperthermia and Nd-YAG laser-induced laserthermia. Nigericin, a polyether ionophore, was used to reduce the intracellular pH to 6.8, while the control cells were maintained at a physiological pH of 7.4. Acidosis increased the heat sensitivity significantly. After the water bath only 75% of the acidotic F9S1 cells were viable, whereas all of the control cells at pH 7.4 survived. When the laser was used, the difference was even more pronounced. Only 9% of the acidotic cells were viable after a 2-min treatment and 0.2% after a 4-min treatment. At physiological pH a 2-min treatment left 41% of the cells viable and a 4-min treatment 2%. This study showed that laserthermia is significantly more effective in killing cells with low intracellular pH than it is in killing cells with normal intracellular pH. The core of a tumour is often acidotic and thus radioresistant. It is suggested that laserthermia could be a good choice when treating acidotic radioresistant cancer cells, and its effect as an adjuvant to radiation therapy should be investigated.
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    Lasers in medical science 10 (1995), S. 157-163 
    ISSN: 1435-604X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Diode lasers are now capable of delivering up to 60 W of power down thin optical fibres, and their medical applications have increased considerably over the past 5 years. Most of the recent experimental and clinical work has been performed using the 805 nm diode laser wavelength, which is more heavily absorbed and is less penetrating than the 1064 nm Nd-YAG wavelength in most tissues. In contact and non-contact mode, the overall tissue effects from the diode laser are similar to the Nd-YAG laser, but with interstitial therapy the 805 nm wavelength produces significantly greater necrosis than the 1064 nm wavelength. Experimental work has established the effectiveness of the diode laser and clinical work has confirmed its suitability for a wide variety of procedures. Diode lasers have the major advantages of being small, compact, portable, efficient, easy to use and virtually maintenance free; they are likely to replace more cumbersome lasers for many medical applications.
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  • 75
    ISSN: 1435-604X
    Keywords: Transmyocardial revascularization ; Lasers ; Coronary artery disease ; Ischaemia ; Tissue hibernation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Transmyocardial revascularization (TMR) is a puncture technique proposed as a solution for patients with coronary artery disease who cannot be efficiently treated with the standard revascularization procedures such as bypass surgery or percutaneous transluminal coronary angioplasty (PTCA). The studies presented in this review have investigated the use of lasers to revascularize ischaemic myocardium. Needle puncture methods are also briefly described. The results from experimental studies are not conclusive but the encouraging clinical reports raise further questions about the mechanism of angina relief.
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  • 76
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    Lasers in medical science 10 (1995), S. 93-104 
    ISSN: 1435-604X
    Keywords: Copper vapour laser ; Electron microscopy ; Illumination time ; Numerical modelling ; Optimal treatment ; Port-wine stain
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract This paper reports the electron microscopy results obtained from two patients who were treated with 5 W of yellow (578 nm) light from a copper vapour laser with an illumination time of 3.6 ms and a 0.3 mm spot diameter. The endpoint of treatment was transient blanching. Following treatment, erythema was observed. There was minimal damage to the epidermis and non-vascular tissue such as the nerve fibres. There was severe damage to the endothelial cells of the ectatic vessels. Twenty-four hours after treatment, platelet activation and collagen were present, indicating that these vessels were no longer viable. Theoretical calculations are used to determine the flow of heat within and away from a 50μm diameter vessel. From this, heating of the entire vessel is shown to occur with illumination times of 4 ms, with minimal heating of the non-vascular tissue. Shorter illuminations do not heat the entire vessel, while the use of longer illumination times will cause excessive damage to the surrounding non-vascular tissue. Illumination times close to 4 ms must be regarded as optimal.
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    Lasers in medical science 10 (1995), S. 13-18 
    ISSN: 1435-604X
    Keywords: Photodynamic therapy ; Larynx ; Oval cavity ; Light dose rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Photodynamic therapy (PDT) has the potential to treat early carcinomas of the oral cavity and larynx while preserving normal tissue. However, normal tissues retain the photosensitizing agents and may be activated by high light fluence and dose rates resulting in normal tissue necrosis. The effects of varying dose rates of light delivery on various tissues in the upper aerodigestive tract have not been evaluated to date and are necessary to determine a ‘therapeutic light dose range’ that will result in selective tumour necrosis. Thirty adult mongrel dogs received intravenous Photofrin, 2 mg kg−1, 48 h prior to PDT treatment. Photodynamic therapy was administered to the tongue, buccal mucosa and larynx with a microlens fibre and implantable cylindrical diffuser at various dose rates from 20 to 125 J cm−2 at 150 mW cm−2. At the same dose rate of light delivery, the tongue was the most sensitive organ, followed by the buccal mucosa, and last by the larynx. The differential tissue effect of identical dose rates of therapy must be taken into account when administering PDT so that selective tumour necrosis with normal tissue preservation may be achieved. This study indicates the need to perform evaluations of the effect of PDT on other tissue types in an animal model with each new photosensitizer prior to administering PDT to those areas in humans.
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  • 78
    ISSN: 1435-604X
    Keywords: Nerve conduction ; Laser therapy ; Skin temperature ; Biostimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract The effects of low-intensity near-infra-red laser irradiation (820 nm; 1.5 and 9.0 J cm−2; pulsed at 12 Hz, 73 Hz and 5 kHz) upon peripheral neurophysiology and skin temperature were investigated using antidromic conduction studies in the human median nerve in vivo. Healthy human volunteers (n = 90) were recruited and allocated randomly to either a control group (n=10) or one of eight experimental groups (two radiant exposures, 1.5 J cm−2 and 9.0 J cm−2 at one of three pulse repetition rates, 12 Hz, 73 Hz or 5 kHz, in addition to a placebo group for each radiant exposure;n = 10 all groups). Analysis of variance (ANOVA) demonstrated a significant (p≤0.05) decrease in skin temperature following irradiation at the lowest radiant exposure (1.5 J cm−2) combined with pulse repetition rates of 73 Hz and 5 kHz, with the greatest effect at 73 Hz. These changes in skin temperature were coupled with increases in negative peak latency (NPL); ie changes in NPL were inversely related to changes in skin temperature. However, in contrast to the authors' previous findings using continuous wave (CW) laser irradiation, differences in NPL were not found to be significant. These findings, therefore, provide little evidence of the neuro-physiological effects of low-intensity infra-red irradiation at the dosage levels and pulse repetition rates used here.
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    Lasers in medical science 10 (1995), S. 267-272 
    ISSN: 1435-604X
    Keywords: Blood flow pulsatility ; Human infants ; Laser Doppler velocimetry ; Retinal blood flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract The present study was conducted to assess the feasibility of laser Doppler velocimetry in young infants, as a prelude to ultimately undertaking such measurements in premature infants. A portable, unidirectional laser Doppler velocimeter was developed based on a Kowa RC-2 hand-held fundus camera. Six infants between 1 and 21 weeks of age were studied. Relative red blood cell velocity (δfmax) at the centre of retinal arteries was measured over approximately 10 heart cycles. A pulsatility parameter (P=1−δfmax.dia/δfmax.sys), a summary index of vascular status, was determined from the average diastolic and systolic values of δfmax. Velocity waveforms were obtained in four of the six infants. Arterial pulsatility for the group was 0.63±0.13. Precise non-invasive measurement of arterial red blood cell velocity waveforms in young infants was achieved. The high signal-to-noise ratio and temporal resolution of this data suggest that relative measurements of retinal blood flow may permit assessment of haemodynamic changes in premature infants.
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    Stochastic environmental research and risk assessment 9 (1995), S. 49-75 
    ISSN: 1436-3259
    Keywords: Flood frequency analysis ; index flood estimators ; L-moments ; GEV distribution ; regionalization ; probability weighted moments
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Our results illustrate the performance of at-site and regional GEV/PWM flood quantile estimators in regions with different coefficients of variation, degrees of regional heterogeneity, record lengths, and number of sites. Analytic approximations of bias and variance are employed. For realistic GEV distributions and short records, the index-flood quantile estimator performs better than a 2-parameter GEV/PWM quantile estimator with a regional shape parameter, or a 3-parameter at-site GEV/PWM quantile estimator, in both humid and especially in arid regions, as long as the degree of regional heterogeneity is moderate. As regional heterogeneity or record lengths increases, 2-parameter estimators quickly dominate. Flood frequency models that assign probabilities larger than 2% to negative flows are unrealistic; experiments employing such distributions provide questionable results. This appraisal generally demonstrates the value of regionalizing estimators of the shape of a flood distribution, and sometimes the coefficient of variation.
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  • 81
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    Stochastic environmental research and risk assessment 9 (1995), S. 105-116 
    ISSN: 1436-3259
    Keywords: Nonlocal ; transport ; dispersion ; heterogeneity ; integro-differential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Analysis from a number of different perspectives has shown diffusion and dispersion in natural porous formations to generally be nonlocal in character, i.e., the mass balance involves integro-partial differential equations. Only in certain asymptotic limits do these laws localize to classical partial differential equations. Compiled within is a resume of nonlocal laws that our group has developed over the last few years for systems with physical, chemical and biological heterogeneity. Analytical tools used to obtain these laws are nonequilibrium and equilibrium statistical mechanics, and first-order spectral-perturbation methods. This paper is an expansion of the material presented at the Waterloo conference held in the memory of Dr. Unny.
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  • 82
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    Stochastic environmental research and risk assessment 9 (1995), S. 133-149 
    ISSN: 1436-3259
    Keywords: moment-equations ; state-space ; numerical integration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract The generation of the second and higher order moment equations for a set of stochastic differential equations based on Ito's differential lemma is difficult, even for small system of equations. From the knowledge of the statistical properties of the Gaussian white noises associated with the parameters and input coefficients of a set of stochastic differential equations of typeA.Ż+B.Z=C(t), a way to automatically generate the second order moment equations in a computer is presented in this paper. The resulting set of first and second order moment equations is also presented in the same state-space form of the original set of stochastic differential equations through a vectorization of the correlation matrix, which takes advantage of its symmetry. The procedure involved here avoids the inversion of matrixA to apply Ito's differential lemma. Therefore, the presented numerical implementation reduces the computational effort required in the formulation and solution of the moment equations. Moreover, other robust and efficient numerical deterministic integration schemes can be equally applied to the solution of the moment equations.
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  • 83
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    Stochastic environmental research and risk assessment 9 (1995), S. 238-238 
    ISSN: 1436-3259
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
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  • 84
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    Stochastic environmental research and risk assessment 9 (1995), S. 269-296 
    ISSN: 1436-3259
    Keywords: Stochastic analysis ; diagrams ; groundwater flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract We present a diagrammatic method for solving stochastic 1-D and 2-D steady-state flow equations in bounded domains. The diagrammatic method results in explicit solutions for the moments of the hydraulic head. This avoids certain numerical constraints encountered in realization-based methods. The diagrammatic technique also allows for the consideration of finite domains or large fluctuations, and is not restricted by distributional assumptions. The results of the method for 1-D and 2-D finite domains are compared with those obtained through a realization-based approach. Mean and variance of head are well reproduced for all log-conductivity variances inputted, including those larger than one. The diagrammatic results also compare favorably to hydraulic head moments derived by standard analytic methods requiring a linearized form of the flow equation.
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  • 85
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    Stochastic environmental research and risk assessment 9 (1995), S. 1-11 
    ISSN: 1436-3259
    Keywords: Environmental management ; extreme values ; hydrology ; stochastic differential equations ; sustainable development ; time series analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Recent developments in stochastic and statistical methods in hydrology and environmental engineering presented in the upcoming sequence of research papers are evaluated, compared and put into proper perspective. These papers are being published as a memorial to Professor T. E. Unny who was a founding Editor of the journalStochastic Hydrology and Hydraulics. As explained in this introductory paper, other activities that took place to celebrate Professor Unny's lifetime academic accomplishments include an international conference held in his honor at the University of Waterloo in June, 1993 and the publication of a four-volume conference proceedings in 1994.
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  • 86
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    Stochastic environmental research and risk assessment 9 (1995), S. 89-104 
    ISSN: 1436-3259
    Keywords: 3D subsurface flow ; stochastic transport ; statístical anisotropy ; heterogeneous porous media
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A methodology for generating three dimensional (3D) flow fields for statistically anisotropic heterogeneous porous media is presented and demonstrated. The simulated flow fields are shown to exhibit the input spatial correlation structure and observe mass continuity. Sample flow fields are presented in the form of cross sectional slices of the 3D formation. These cross sections demonstrate visually the characteristics of subsurface flow. The method was found to be faster than traditional techniques in terms of its computational requirements. Given this method, it is possible to generate the large number of realizations of a velocity field necessary to compute high order statistics in transport problems.
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  • 87
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    Stochastic environmental research and risk assessment 9 (1995), S. 151-170 
    ISSN: 1436-3259
    Keywords: Environmental regulation ; compliance ; game theory ; whistle-blowing ; reporting system ; water quality management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A formal mathematical model is developed to ascertain the effectiveness of a reporting system for improving the enforcement of environmental laws and regulations when reports are costly. To model realistic enforcement problems arising over environmental issues such as compliance to water and air quality standards, a formal enforcement model is constructed using concepts from probability and statistics, non-cooperative game theory, and economics. In order to demonstrate clearly the benefits gained when an environmental agency takes advantage of a reporting system, a formal enforcement model with a costly reporting system is rigorously compared to one with no reporting system. The calculation and comparison of Nash equilibria for a range of values of model parameters indicates under what conditions a reporting system can be truly effective. Overall, it is found that a reporting system, such as whistle-blowing, can be helpful for reducing violations of environmental standards, thereby maintaining better environmental quality.
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  • 88
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    Stochastic environmental research and risk assessment 9 (1995), S. 207-213 
    ISSN: 1436-3259
    Keywords: Abelson-Tukey coefficients ; binary time series ; detection ; floods ; monotone trend ; point process ; Rio Negro ; time series ; trend
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract A sequence of occurrence times of floods may be considered to be part of a realization of a binary-valued time series or of a stochastic point process. In this paper a criterion for detecting the presence of a monotonic trend in the rate of the process is considered. The criterion is based on linear functions of the data with the coefficients chosen to emphasize a monotonic rate. In the case that the process is stationary and mixing, the null distribution of the test statistic is approximately standard normal.
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  • 89
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    Stochastic environmental research and risk assessment 9 (1995), S. 239-267 
    ISSN: 1436-3259
    Keywords: Stochastic analysis ; multiphase flow ; porous media
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Stochastic analysis of steady-state multiphase (water, oil, and air) flow in heterogeneous porous media was performed using the perturbation theory and spectral representation techniques. The gas phase is assumed to have constant pressure. The governing equations describing the flow of oil and water are coupled and nonlinear. The key stochastic input variables are intrinsic permeability,k, and the soil grain size distribution index, α. Three different stochastic combinations of these two input parameters were considered. The perturbation/spectral analysis was used to develop closed-form expressions that describe stochastic variability of key output processes, such as capillary and individual phase pressures and specific discharges. The analysis also included the derivation of the mean flow equations and estimation of the effective flow properties. The impact of the spatial variability ofk and α on the effective conductivities and the variances of pressures and specific discharges was examined.
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  • 90
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    Stochastic environmental research and risk assessment 9 (1995), S. 297-323 
    ISSN: 1436-3259
    Keywords: Stochastic analysis ; unsaturated transport ; fractals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Architecture, Civil Engineering, Surveying , Energy, Environment Protection, Nuclear Power Engineering , Geography , Geosciences
    Notes: Abstract Within the framework of stochastic theory and the spectral perturbation techniques, three-dimensional dispersion in partially saturated soils with fractal log hydraulic conductivity distribution is analyzed. Our analysis is focused on the impact of fractal dimension of log hydraulic conductivity distribution, local dispersivity, and unsaturated flow parameters, such as the soil poresize distribution parameter and the moisture distribution parameter, on the spreading behavior of solute plume and the concentration variance. Approximate analytical solutions to the stochastic partial differential equations are derived for the variance of asymptotic solute concentration and asymptotic macrodispersivities.
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  • 91
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    Lasers in medical science 10 (1995), S. 19-24 
    ISSN: 1435-604X
    Keywords: Photodynamic therapy ; Light dosimetry ; Fibre optic probes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract We describe the calibration of fibre optic probes used to perform in vivo light dosimetry studies during the treatment of skin lesions by photodynamic therapy. Results from six individual detectors show that the linearity of the calibration and the calculated radiant energy fluence rate within a liquid phantom are independent of the type and sensitivity of the probe. The method of calibration is also shown to yield the optical interaction coefficients of the phantom.
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  • 92
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    Lasers in medical science 10 (1995), S. 3-8 
    ISSN: 1435-604X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract The use of therapeutic lasers depends on four basic laser-tissue interactions; photothermal, photochemical (PDT), mechanical and ablative. There is no place for mechanical and ablative interactions in oncology; PDT will be the subject of a further review and the subject of this review is therefore the photothermal reaction. Thermal lasers have been in routine use in oncology for the last 10–15 years. These lasers, emitting in the visible or infra-red parts of the spectrum, are used to produce three basic effects; hyperthermia, coagulation and vaporization. Other energy sources beside lasers can also be used to produce these tissue effects but lasers seem to possess certain basic advantages. In comparison with monopolar or bipolar diathermy and heater probes, lasers can deliver more power, more accurately at the target tissue with better control of damage and a wider range of effects. In comparison with microwave and ultrasound therapy, lasers are again more precise and can be used with more compact and accurate delivery devices. In gastroenterological surgery (as opposed to endoscopy), neurosurgery and gynaecology, laser light can be delivered via a handpiece to cut and coagulate. In ENT and also some applications of gynaecology lasers can also be used via a microscope. In endoscopic surgery laser light is delivered through an optical fibre within the endoscope—this for the time being precludes the use of the CO2 laser for these applications. More recently, the laser fibre can be placed directly within tumour tissue for interstitial thermal therapy of liver metastases, pancreatic tumours and brain tumours. The future use of thermal lasers in oncology depends very much on the results of properly controlled comparative studies against PDT and non-laser thermal devices; in addition their use may well be widened to include some curative procedures; up until now their use has very much been restricted to palliative therapy except where they are used as an adjunctive cutting device alongside conventional curative surgery.
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  • 93
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    Lasers in medical science 10 (1995), S. 189-192 
    ISSN: 1435-604X
    Keywords: Stomach ; Polyposis ; Nd-YAG laser ; Therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Thirteen patients with gastric polyposis (113 polyps) were treated by endoscopic Nd-YAG laser irradiation. Among them there were five cases with adenomas, six with hyperplastic polyps and two with inflammatory polyps. Ninety-six polyps were 〈1 cm, 13 polyps were ⩾ 1 cm, and four polyps were ⩾ 2 cm. In the patient who had the largest number of lesions, 22 polyps were found at endoscopic examination. All but two patients were regularly followed up endoscopically for 2–5 years after treatment and showed no sign of recurrence. Mild bleeding occurred in three cases. No perforation or any other serious complications occurred. The results were encouraging. It is concluded that endoscopic Nd-YAG laser ablation of gastric polyposis is effective, simple to perform, safe and deserves recommendation.
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    Lasers in medical science 10 (1995), S. 213-216 
    ISSN: 1435-604X
    Keywords: Granular cell tumours ; CO2 Laser treatment ; Electron microscopic examinations ; Tongue ; Larynx
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Seven cases of granular cell Abrikossoff tumours of the larynx and tongue are reported: four in the tongue and three in the larynx. All of these tumours were removed with the carbon dioxide (CO2) laser. The anatomical site of the origin and clinical features of granular cell tumours (GCT) are not specific. Histological, light microscopic, electron microscopic (EM) and immunohistochemical studies are required for diagnosis. The histogenesis and cellular derivation of GCTs is still controversial. The biological potential and lack of cellular atypia define a benign process. However, it is important to take into account that these tumours have ill-defined borders without a capsule. Radiation therapy has proved ineffective in the past. Surgical excision with a wide margin is required. Because of numerous advantages, for example, no bleeding, no oedema, minimal pain and quick recovery, CO2 laser removal is the treatment of choice. The authors have not seen any recurrence or complications.
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  • 95
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    Keywords: Port-wine stain ; Blood vessel ; Pulse duration ; Energy threshold ; Selective photothermolysis ; Monte Carlo ; Thermal diffusion ; Vascular injury
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Monte Carlo simulation of laser energy deposition in a port-wine stain (PWS) skin model and numerical solution of the thermal diffusion equation have been used to calculate threshold energies for thermal injury of PWS blood vessels for different vessel sizes and laser pulse durations. It has been assumed that an average vessel temperature rise of 65
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  • 96
    ISSN: 1435-604X
    Keywords: Radiation effects ; In vitro maturation ; In vitro fertilization ; HeNe laser irradiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract A study was made of the effects of low power laser irradiation on in vitro oocyte maturation rates and subsequent fertilization of immature bovine oocytes. Immature bovine oocytes from cows sacrificed at a slaughterhouse were irradiated with Helium-Neon laser (HeNe laser) irradiation at an energy density of 0.4 and 2.0 J cm−2. An oocyte group was left untreated, serving as control group. All oocytes were matured and fertilized in TCM-199 medium supplemented with 20% fetal calf serum (FCS). Maturation and fertilization rates obtained in the irradiated oocytes group were lower (p〈0.001 andp〈0.05, respectively) than those of the control group. Furthermore, the laser-treated oocytes showed important degenerative changes on both cytoplasm and chromosomes in comparison with untreated control oocytes which showed a homogenous cytoplasm and disperse chromosomes. It is concluded that the application of HeNe laser irradiation at 0.4 and 2.0 J cm−2 energy densities has a detrimental effect on in vitro maturation and fertilization process of immature bovine oocytes.
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  • 97
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    Keywords: Photodynamic therapy ; Haematoporphyrin derivative ; In vivo ; Laser ; Light source ; Murine tumour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract The performance of a low cost, table-top/portable light source was tested against an argon ion pumped dye laser for in vivo photodynamic therapy (PDT). The prototype delivers up to 1 W via a 4 mm flexible lightguide within a 30 nm bandwidth centred at any wavelength from 300 nm to 1200 nm at fluence rates of up to 8 W cm−2. An in situ bioassay using regrowth delay of tumour T50/80 was used to quantify the relative efficacy of the prototype with a laser. The tumours were sensitized with haematoporphyrin derivative (HpD) and externally irradiated. There was no significant difference in the response of the tumour to treatment between the two light sources (p = 0.69). Mean growth delays ranged from 2 days (light dose 10 J cm−2) to 20 days (light dose 100 J cm−2). The estimate for the difference in means (laser minus prototype growth delay) was only 0.66 days and was not statistically significant. This in vivo study demonstrates that the prototype is equivalent to a laser in PDT effect. The device has low capital/running cost, is simple to use and is one of the most powerful, spectrally efficient non-laser PDT sources available.
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  • 98
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    Keywords: Photodynamic therapy ; Isotropic fibre optic light diffusers ; Construction of diffusers ; Quality assurance of diffusers ; Calibration of diffusers ; Goniometer ; Integrating sphere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract Spherical isotropic fibre optic light diffusers are used in photodynamic therapy either as a light source or as a light detector. The construction of light diffusers using different materials is described, viz. an optical method involving local polymerization of a dental fissure sealant, which is referred to as the Henderson method, and a second method using plastic or ceramic pre-fabricated spheres. Quality tests necessary for reliable clinical use are presented for the mechanical strength, output power and isotropy. The maximum pull-off force and blow-off output power for the different kinds of diffusers were determined. The calibration procedures are given for measurement of the output power and wavelength of the light emitted by a diffuser and for measurement of the fluence rate by a light-detecting diffuser, using a compact integrating sphere device. With all types of diffusers described, an isotropy can be obtained of better than ± 20% measured over a 320° angle for spheres as small as ≈ 1 mm. Larger ceramic diffusers are particularly suitable for delivering high output powers. A 3-mm-diameter ceramic diffuser mounted on a 600-μm-core fibre can emit up to ≈ 5 W of continuous wave (CW) visible light in air. Diffusers used for light detection can measure the light fluence rate in tissue with ≈15% accuracy or better if calibration factors are determined for each individual probe.
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    Lasers in medical science 10 (1995), S. 155-155 
    ISSN: 1435-604X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
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  • 100
    ISSN: 1435-604X
    Keywords: Bone histology ; Holmium-YAG laser ; Infra-red lasers ; Laser surgery ; Photo ablation ; Otology ; Stapes ; Otosclerosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Physics , Technology
    Notes: Abstract The effect of tissue micro-architecture and water content on ablation rates in bone is examined. Precisely machined and prepared porcine calvarial lamellar and cortical bone were ablated with a Holmium-YAG laser (λ=2.1Μm). Lamellar and cortical bone differ substantially in their tissue micro-architecture. Both are porous hard tissues, which differ predominantly in size and distribution of pores within the bone matrix. These hard tissues were ablated under physiological (wet) and chemically dehydrated conditions. The ablation rates over the range of energy densities examined assumes many linear characteristics. Ablation rate (as a function of fluence) is considerably higher for dehydrated cortical bone (4.7Μm cm2 J−1) compared to fresh cortical bone (1.49Μm cm2 J−1). This trend is also observed in lamellar bone (2.31Μm cm2 J−1 for wet and 0.37Μm cm2 J−1 for dry). Under both physiological and dehydrated conditions, cortical bone was ablated faster. Mechanisms accounting for these observations are discussed.
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