ALBERT

Notizen: The global positioning system (GPS) is used increasingly to control horizontal and vertical displacement of large civil constructions. The displacements can occur over varius time scales. For example, in case of the loading test of a bridge, the time span between measurements is on the order of 30 min. The achievable precision in the vertical component and its relation to residual multiplath effects become critically important in such aaplications. A multipath-to-noise ratio (MNR) on individual satellites is introduced to quantify the multipath effects. © 2000 John Wiley & Sons, Inc.

Notizen: In this article, initial results are presented of a method to improve fast carrier phase ambiguity resolution over longer baselines (with lengths up to about 200 km). The ionospheric delays in the global positioning system (GPS) data of these long baselines mainly hamper successful integer ambiguity resolution, a prerequisite to obtain precise positions within very short observation time spans. A way to correct the data for significant ionospheric effects is to have a GPS user operate within an active or permanently operating network use ionospheric estimates from this network. A simple way to do so is to interpolate these ionospheric estimates based on the expected spatial behaviour of the ionospheric delays. In this article such a technique is demonstrated for the Dutch Active Control Network (AGRS.NL). One hour of data is used from 4 of the 5 reference stations to obtain very precise ionospheric corrections after fixing of the integer ambiguities within this network. This is no problem because of the relatively long observation time span and known positions of the stations of the AGRS.NL. Next these interpolated corrections are used to correct the GPS data from the fifth station for its ionospheric effects. Initial conclusions about the performance of this technique are drawn in terms of improvement of integer ambiguity resolution for this baseline. © 1999 John Wiley & Sons, Inc.

Notizen: Since global positioning system (GPS) measurements are ranges (code) and biased ranges (carrier), it seems natural to model them as ranges and determine the biases. This is particularly compelling since the double-difference range biases turn out to be integers. At some level there is also an elegance, perhaps therefore a naturalness, to modeling the carrier measurements as time differences of double differences. While something is lost something else is gained. Here we apply the proven delayed-state Kalman filter to processing carrier phase measurements as triple differences. In practice we process these triple differences along with double-difference code measurements. We also treat the measurement error as, mostly, Gauss-Markov states to be determined. Many of the details are discussed and experimental results are included. These demonstrate that excellent performance can be obtained if the Kalman filter modeling is done carefully. © 2000 John Wiley & Sons, Inc.

Notizen: A third civil frequency at 1176.45 MHz will be added to the Global Positioning System (GPS). This new frequency will bring a number of benefits. The aviation user will be one of the prime beneficiaries because the new frequency is in a protected aviation band. Thus, the system will be more robust against interference and jamming. The carrier-phase differential user will also be a prime beneficiary as long as his application has a reasonably short baseline. It is this high accuracy use that is explored in some depth. The process of forming linear combinations of both the code and carrier-phase measurements is studied, and the benefits and problems are explained. © 2000 John Wiley & Sons, Inc.

Notizen: The ionospheric range delay is highly variable both in space and in time. The ionospheric correlation distance is defined as the distance over which a measurement of the difference from monthly mean ionospheric range delay at one location can be used to determine the difference from mean conditions at a second location. The percentage improvement required is dependent upon the actual correlation coefficient, which must be relatively large to produce a significant improvement over differences from average conditions at two stations. Results of studies of the correlation distance show that, in order to obtain even a 28% improvement over monthly median conditions, the measurement location must be within approximately 3,000 km in longitude or 1,800 km in latitude from the location where the update from monthly mean conditions is required, at least in the mid-latitude region. Another study showed that, in order to be able to determine an improvement of 1 m in ionospheric range delay from average ionospheric conditions at a location remote from where the actual measurement of range delay is made, the measurement must be within approximately 500 km of that location. © 2000 John Wiley & Sons, Inc.

Notizen: At the Delft University of Technology (DUT), the data of six stations participating in the first international GLONASS (Global Navigation Satellite System, the Russian counterpart of GPS) tracking campaign, IGEX-98, were analyzed with integrity monitoring software. The software was developed at the Department of Mathematical Geodesy and Positioning of DUT. The main function of this software is to detect slips and outliers in phase and code observations in real time. In addition, the software also allowe the validation of the information contained in the broadcast navigation messages. The results of the IGEX-98 data analyses will be presented in a three-part series. In this second part of the series, GLONASS outlier and slip statistics will be discussed in detail. The first part was concerned with the availability of GLONASS observations, while in the third one the broadcast navigation message validation results will be considered. © 2000 John Wiley & Sons, Inc.

Notizen: The forthcoming World Radiocommunication Conference (WRC) will deal with frequency allocation and protection issues that are of fundamental importance to GNSS (Global Navigation Satellite System) and GPS (Global Positioning System), which is a component of GNSS. In many countries, GPS L1 and L2 are not protected, and much needs to be done to obtain a frequency allocation for GPS L5. A brief explanation of the International Telecommunication Union (ITU) and how it can impact satellite navigation at its World Radiocommunication Conference in 2000 (WRC-2000) is provided. © 2000 John Wiley & Sons, Inc.

Notizen: Positioning and navigation – as are presently possible with the American Global Positioning System (GPS) and the Russian GLONASS system – is briefly reviewed. Deficiencies, which have led to augmentations like the European Geostationary Navigation Overlay System (EGNOS), are outlined. Europe's decision to get involved in the definition and possible set-up of a Global Navigation Satellite System (GNSS) of the second generation (GNSS-2), called Galileo, is discussed in detail as well as the GPS modernization program that might take place during the sample phase. Finally, some brief thoughts on the benefit of GNSS-2 for geodesy and surveying are given. © 2000 John Wiley & Sons, Inc.

Notizen: The International GLONASS Experiment 1998 (IGEX-98) was the first international tracking campaign of the Russian counterpart to the Global Positioning System (GPS), GLONASS. Started in October 1998, the campaign was originally scheduled to last for three months. However, the launch of additional GLONASS satellites and a widespread enthusiasm among the participants led to an indefinite continuation of the campaign on a “best effort” basis. At the Delft University of Technology, the data of six IGEX-98 stations have been analyzed in detail with integrity monitoring software, developed at the Department of Mathematical Geodesy and Positioning of the University. The software aims to detect outliers and slips in code and phase observations in real time. In addition, the software also allows the validation of the information contained in the broadcast navigation messages. The results of the IGEX-98 data analyses will be presented in a three-part series. In the second part, GLONASS outlier and slips statistics will be discussed, while in the third part the anomaly detection results of the GLONASS and GPS messages will be shown. In this first part of the series, however, the most basic of all statistics will be considered: a simple day-to-day count of the number of GLONASS and GPS observations. Although simple, this statistic yields a surprising amount of information both on the availability of the GLONASS satellites and on the peculiarities of some of the receiver makes participating in the IGEX-98 campaign. © 2000 John Wiley & Sons, Inc.

Notizen: The Federal Aviation Administration (FAA) is developing the wide-area augmentation system (WAAS) to supplement the Global Positioning System (GPS) and serve as a single en-route navigation aid. The program traveled a rocky road so far. We compare the original concept of WAAS with its current scaled down version, analyze the changed perspectives with respect to the utility of GPS for air navigation and the concomitant role of WAAS, and explore the future of GPS/WAAS. © 2000 John Wiley & Sons, Inc.

Notizen: There are various applications in which a Global Positioning System (GPS) sensor only down-converts and digitizes the received GPS signal and sends the digitized data to a processor, where the processor software performs all the correlation, search/track operations, navigation solution, and so on. Among the applications are military and commercial ones (e. g., GPS(Communication handheld sets, people tracking systems). A major problem with the Software GPS Receiver is the large computing resources required for correlation or acquisition of the GPS signal. In this article, several possible approaches for reducing computing resources will be introduced and analyzed. It will be shown that the performance of the GPS software design strongly depends on the features of the computer hardware. Implementations will be described on the TMS320C6201 processor and the Pentium II. Experimental results will be demonstrated by processing of real GPS signals. A complete 16-channel GPS receiver was implemented on the single TMS320C6201 processor in real-time mode and on the Pentium II processor with a duty cycle of about 50%. © 2000 John Wiley & Sons, Inc.

Notizen: The law affects the Global Positioning System (GPS) industry both on a macro and on a micro level. On a macro level, issues such as future regulation of telematics, frequency spectrum allocation, and international agreements will shape the future of the industry. On a micro level, GPS companies can benefit from knowledge of legal pitfalls common in the high technology arena. Many thanks to Ingrid Lagarrigue, a French aviation and space lawyer specializing in Global Navigation Satellite legal issues, for her assistance and comments. © 2000 John Wiley & Sons, Inc.

Notizen: A number of statistic Global Positioning System (GPS) measurement campaigns have been made on a floating Antarctic ice shelf, the Amery Ice Shelf, as part of ongoing glaciological studies designed to investigate the ice shelf dynamics, grounding zone definition, and ice shelf strain. Such studies ar fundamental to improving out knowledge of the Antarctic ice-sheet mass balance and dynamical models of ice sheet/ocean interaction. This article describes two techniques used to process the statistic GPS data. One approach uses a segmented version of the classical static methodology, and the other approach adopts a new sequential processing technique. Both approaches yield similar results for the station coordinates and demonstrate the potential of GPS for extracting the tidal signal on the ice shelves and giving information on the dynamical motion of the ice sheet. To verify our results for the vertical component, we compare the ice shelf GPS tidal signal with a tidal model derived from tide gauge measurements at nearby Beaver Lake. Comparison of the GPS results with the tide model give good agreement in amplitude at the few cm level (GPS results always larger) but clearly shows evidence of phase propagation of the ocean tidal wave under the ice shelf. Improving the resolution of the tides over the ice shelves will be of tremendous benefit for future satellite missions, such as Ice, Cloud and Land Elevation Satellite (ICESAT), and the integrated use of GPS and satellite data will be fundamental for any on-going Antarctic ice sheet mass balance studies. © 2000 John Wiley & Sons, Inc.

Notizen: A new computer-aided design (CAD) program called Falcon 3.0 has been created to simulate and evaluate receiver designs. This CAD tool aims to solve tasks at the design stage of navigation receivers that operate with signals from Navigational Satellite Time and Ranging (NAVSTAR) and Global Navigational Satellite System (GLONASS). Specific tasks include: · Defining the receiver frequency plan (frequencies of oscillators and filters that guarantee accuracy of the receiver) · Specifying parameters for the digital processing of received signal · Computing interpath and interchannel biases · Computing statistical characteristics of correlation signals I, Q, dl, and dQ · Calculating noise and multipath errors of measurements · Determeining energy losses This CAD tool has been used in the design of receivers such as Javad Positioning Systems (JPS) Legacy, Regency, Odyssey, and Eurocard and in the prediction of their accuracy. It has been shown that experimental and predicted data agree well. © 2000 John Wiley & Sons, Inc.

Notizen: The recent development of low-cost, high-precision oscillators has allowed many applications in various fields to become financially feasible. The stability of an oscillator is ultimatively what determines its usefulness for a certain application, and is therefore desirable to quantify. Current methods of evaluating stability require a direct comparison of the oscillator under test (OUT) with amore stable reference oscillator, the cost of which often offsets the initial benefit of a low-cost device. However, a relatively inexpensive Global Positioning System (GPS) receiver is capable of exploiting the highly stable GPS time scale, thus obviating the need for an expensive reference oscillator. By allowing the OUT to drive a GPS receiver, and processing the data with precise GPS orbits and clock corrections to eliminate the effects of selective availability (SA), the time series of computed clock offsets provides a measure of the oscillator's stability relative to GPS time. The use of GPS for assessing clock stability in the time domain is evaluated herein via the computation of Allan variance values. Performance of one rubidium and three ovenized crystal oscillator are investigated. Results show the method is limited to time intervals less than about two seconds or longer than about 300 seconds, where the effects of measurement noise and residual SA is less pronounced. © 2000 John Wiley & Sons, Inc.

Notizen: Patricia Doherty joins the regular contributors of this column to discuss the correlation between measurements of solar 10.7 cm radio flux and ionospheric range delay effects on GPS. Mrs. Doherty has extensive experience in the analysis of ionospheric range delays from worldwide systems and in the utilization and development of analytical and theoretical models of the Earth's ionosphere. Ionospheric range delay effects on GPS and other satellite ranging systems are directly proportional to the Total Electron Content (TEC) encountered along slant paths from a satellite to a ground location. TEC is a highly variable and complex parameer that is a function of geographic location, local time, season, geomagnetic activity, and solar activity. When insufficiently accounted for, ionospheric TEC can seriously limit the performance of satellite ranging applications. Since the ionosphere is a dispersive medium, dual-frequency Global Positoning System (GPS) users can make automatic corrections for ionospheric range delay by computing the apparent difference in the time delays between the two signals. Single-frequency GPS users must depend on alternate methods to account for the ionospheric range delay. Various models of the ionosphere have been used to provide estimates of ionospheric range delay. These models range from the GPS system's simple eight-coefficient algorithm designed to correct for approximately 50% rms of the TEC, to state-of-the-art models derived from physical first principles, which can correct for up to 70 to 80% rms of the TEC but at a much greater computational cost. In an effort to improve corrections for the day-to-day variability of the ionosphere, some attempts have been made to predict the TEC by using the daily values of solar 10.7 cm radio flux (F10,7). The purpose of this article is to show that this type of prediction is not useful due to irregular, and sometimes very poor, correlation between daily values of TEC and F10.7. Long-term measurements of solar radio flux, however, have been shown to be well correlated with monthly mean TEC, as well as with the critical frequency of the inonospheric F2 region (foF2), which is proportional to the electron density at the peak of the ionospheric F2 region. © 2000 John Wiley & Sons, Inc.

Notizen: Neural networks have been proposed as nonlinear filters in a variety of applications that involve nonlinear processing of input signals; examples include blind signal separation, image registration, and blind deconvolution. The Global Positioning System (GPS) navigation equations are nonlinear (quadratic) in nature, and a direct closed form solution of the GPS navigation equations does not exist. This article presents a new approach to solving the GPS pseudorange equations using three-layer neural networks. A three-layer radial basis function (RBF) neural network is designed, which solves the non-linear GPS pseudorange equations directly as opposed to the linear least squares or extended Kalman filter approaches in traditional GPS receivers. For training the neural network, a carefully selected cost function is minimized using a variation of the classical conjugate gradient algorithm such that training time for the neural network is reasonable. Simulations have been performed at SiRF Technology Inc. that show stable behavior even under bad geometry conditions where the traditional recursive least squares and extended Kalman filter approaches show high sensitivity to measurement errors. Under good geometry conditions the neural network solution shows slightly improved noise performance compared to the expected performance of traditional leas squares solution. Simulations have been performed with additive white Gaussian noise and correlated noise models to evaluate the performance of the trained neural network. © 2000 John Wiley & Sons, Inc.

Notizen: In order to achieve to GPS solutions of first-order accuracy and integrity, carrier phase observations as well as pseudorange observations have to be adjusted with respect to a linear/linearized model. Here the problem of mixed integer-real valued parameter adjustment (IRA) is met. Indeed, integer cycle ambiguity unknowns have to be estimated and tested. At first we review the three concepts to deal with IRA: (i) DDD or triple difference observations are produced by a properly chosen difference operator and choice of basis, namely being free of integer-valued unknowns (ii) The real-valued unknown parameters are eliminated by a Gauss elimination step while the remaining integer-valued unknown parameters (initial cycle ambiguities) are determined by Quadratic Programming and (iii) a RA substitute model is firstly implemented (real-valued estimates of initial cycle ambiguities) and secondly a minimum distance map is designed which operates on the real-valued approximation of integers with respect to the integer data in a lattice. This is the place where the integer Gram-Schmidt orthogonalization by means of the LLL algorithm (modified LLL algorithm) is applied being illustrated by four examples. In particular, we prove that in general it is impossible to transform an oblique base of a lattice to an orthogonal base by Gram-Schmidt orthogonalization where its matrix enties are integer. The volume preserving Gram-Schmidt orthogonalization operator constraint to integer entries produces “almost orthogonal” bases which, in turn, can be used to produce the integer-valued unknown parameters (initial cycle ambiguities) from the LLL algorithm (modified LLL algorithm). Systematic errors generated by “almost orthogonal” lattice bases are quantified by A. K. Lenstra et al. (1982) as well as M. Pohst (1987). The solution point ${\hat z}$ of Integer Least Squares generated by the LLL algorithm is ${\hat z}$ = (L')−1[L'◯] ∈ ℤ m where L is the lower triangular Gram-Schmidt matrix rounded to nearest integers, [L], and ${\hat z}$ = [L'◯] are the nearest integers of L'◯, ◯ being the real valued approximation of z ∈ ℤ m , the m-dimensional lattice space Λ. Indeed due to “almost orthogonality” of the integer Gram-Schmidt procedure, the solution point ${\hat z}$ is only suboptimal, only close to “least squares.” © 2000 John Wiley & Sons, Inc.

Notizen: At the Delft University of Technology (DUT), data of six stations participating in the first international GLONASS tracking campaign, IGEX-98, were analyzed with integrity monitoring software. The software was developed at the Department of Mathematical Geodesy and Positioning of DUT. The main function of the software is to detect slips and outliers in phase and code observations in real time. In addition, the software also allows the validation of the information contained in the broadcast navigation messages. The results of the IGEX-98 data analyses are presented in a three part series. In this third and final part of the series, GLONASS and GPS navigation message validation results will be discussed in detail. The first part was concerned with the availability of GLONASS observations (Jonkman & de Jong, 2000a), while in the second part, GLONASS slip and outlier statistics were considered (Jonkman & de Jong, 2000b). The discussion of the navigation message validation results concentrates on anomalies detected in the data of an IGEX-98 station in Switzerland. Data collected at this station from September 1998 to December 1999 was analyized. In all, 19 anomalies were detected by the integrity monitoring software, 8 in GLONASS messages and 11 in GPS messages. The cause of the anomalies was established by evaluating the original data files, studying official bulletins of the GLONASS and GPS ground segments, and in some cases tracing the anomaly through the complete IGEX-98 network. © 2000 John Wiley & Sons, Inc.

Notizen: Zusammenfassung An ausgewachsenen Rehen wurden in Stoffwechselkäfigen Stickstoff-(N-)Bilanz-Versuche durchgeführt. Die Tiere bekamen pelletierte Alleinfutter vorgelegt. Eine proteinarme Basisdiät mit 5,6% Rohprotein (RP) in der Trockensubstanz wurde mit wechselnden Mengen gereinigten Sojaproteins verschnitten, so daß Diäten mit bis zu 21,8% RP entstanden. Die N-Verluste über den Kot betrugen 6,1 g/kg Futtertrockensubstanz. Vom scheinbar verdauten N wurden bei Gewichtskonstanz der Tiere 94,5% im Harn wiedergefunden. Bei der proteinarmen Basisdiät ging die Harn-N-Ausscheidung auf 0,12 g/Tag/kg Körpergewicht0,75 zurück. Auch mit dieser Diät waren die Rehe noch in der Lage, die N-Bilanz positiv zu gestalten und zuzunehmen. Der tägliche Bedarf zur Erhaltung bei einem Reh von 20 kg beträgt nach diesen Ergebnissen 7,5 g scheinbar verdauliches RP. Bei dem verwendeten Versuchsfutter entsprach das 24,3 g RP/Tag im Futter oder 5,5% RP in der Futtertrockensubstanz. Dieser Erhaltungsbedarf ist niedriger, als bisher für das Reh angenommen wurde, entspricht dagegen recht gut dem Bedarf von Hauswiederkäuern.

Notizen: Zusammenfassung In den Julischen Alpen Sloweniens wurden von 1967 bis 1973 78 erlegte Gamsgaisen verschiedenen Alters auf Trächtigkeit untersucht. Davon waren 69 als sog.Geltgaisen im Wege der Auslese abgeschossen worden. 9 kitzeführende aber speziell für die Untersuchungszwecke. Bei beiden Gruppen hatte die Trächtigkeit den gleichen Prozentsatz von 80, bezogen auf alle Gaisen vom dritten bis achtzehnten Lebensjahr. Im dritten Lebensjahr brunftete ein Teil der Gaisen erfolgreich (war trächtig), im vierten Lebensjahr etwas weniger als die Hälfte, im mittleren Alter (4–10 Jahre) lag die Trächtigkeit bei 90%, bei älteren Stücken bei 83%. Auf den Eierstöcken wurden 8% mehr Gelbkörperchen gefunden, als der Zahl der Embryonen entsprach. Bei einigen überzähligen Gelbkörperchen handelte es sich um atretische Formen, was bedeutet, daß die Gaisen zweimal ovulierten.

Notizen: Zusammenfassung Berichtet wird über Volierenversuche mit Rebhühnern in den Jahren 1968 bis 1973. Aus den Versuchen wird gefolgert, daß die Winterfütterung von Rebhühnern allein auf Sämereienbasis möglich ist. Grünfutter ist im Winter grundsätzlich nicht notwendig. Bevorzugt werden vom Rebhuhn die Samen des Glanzgrases (Spitz,Ph. canariensis), der Hirse (Panicum sp.Setaria sp.), des Hanfes (Cannabis sativa), des Thimothes (Phleum pratense), des Deutschen Weidelgrases (Lolium perenne) und des weißen Straußgrases (Agrostis alba genuina). Kaum Zuspruch fanden die Sämereien verschiedener Wildkräuter wie Melde,Atriplex sp., Wegerich,Plantago sp., Floh- und pfirsichblättriger Knöterich,Polygonum persicaria bzw.lapathifolium und Sauerampfer,Rumex sp.

Notizen: Zusammenfassung Im Winter 1972/73 wurde das agonistische Verhalten und die Rangordnung von individuell markierten Rehen an einer Winterfütterung in den Voralpen der Ostschweiz untersucht. Die Rangordnung war beinahe linear und mehr oder weniger stabil. Rangverlust wurde nach Geweihabwurf und Verletzung, Ranggewinn nach Fegen des Geweihs beobachtet. Adulte Böcke dominierten alle anderen Klassen, und Kitzböcke dominierten fast alle Geißen. Die Beziehung zwischen Rang und Alter, Geweihgröße, Distanz zwischen Futterstelle und Sommereinstand sowie erstem Beobachtungsdatum an der Winterfütterung wurde mit Rangkorrelationen geprüft. Bei adulten Böcken hatte nur die Distanz zum Sommereinstand einen Einfluß auf die Ranghöhe: je kürzer diese Distanz, desto dominanter der Bock. Dies und die Tatsache, daß die ranghöchsten Böcke am aggressivsten waren und als einzige Markierverhalten zeigten, legt die Vermutung nahe, daß Rehböcke auch im Winter potentiell territorial sind. Geißen waren um so ranghöher, je früher sie erstmals an der Winterfütterung beobachtet worden waren. Dagegen hatte das Alter keinen Einfluß auf die Ranghöhe. In Besitz genommene Futterhaufen wurden manchmal erfolgreich gegen ranghöhere Tiere verteidigt.

Notizen: Zusammenfassung Während der Jahre 1970 bis 1973 wurden 800 Organ-, Fett- und Eierproben von 26 Wildtierarten gaschromatographisch auf Rückstände an chlorierten Pesticiden und PCBs hin untersucht. Mit über 90% waren HCB und Lindan + Isomere am verbreitetsten (Tab. 1). Die Pesticid- und PCB-Konzentration im Leber- und Fettgewebe lag bei Herbivora im ppb-Bereich (Tab. 2 und 3), stieg jedoch im Rahmen der Nahrungskette bei Carnivora auf das Fünffache der bei Pflanzenfressern gefundenen Werte (Tab. 2 und 3). Die höchsten Rückstandsmengen-v.a. an DDE, DDT und Isomeren-fanden wir in Greifvogeleiern und in Dorschleber (ppm-Bereich siehe Tab. 2 und 3).

Notizen: Zusammenfassung 1655 Rotfüchse—871 Rüden, 591 Fähen und 193 ohne Geschlechtsbestimmung—von denen sich durch die Laboruntersuchungen 290 als tollwütig erwiesen, wurden nach dem Zahnalter (Zahndurchbruch,-wechsel und-abnutzung) sowie auf Grund des Linsentrockengewichts nach der Methode vonvan Haaften (1969) auf ihr Alter untersucht und die beiden Methoden miteinander verglichen. Beide Arten der Altersfeststellung liefern für Jungfüchse und Altfüchse bis zu 2 Jahren verläßliche Ergebnisse. Bei älteren Füchsen versagt die Zahnaltersbestimmung. Auf Grund mangelnder Vergleichsmöglichkeiten mit Füchsen bekannten Alters läßt sich zwar über die Sicherheit der Altersbestimmung mittels Linsentrockengewicht bei älteren als 2jährigen Füchsen noch keine endgültige Aussage machen, doch erscheint die Methode aufschlußreicher als die anderen Arten der Altersbestimmung. Tabelle 5 gibt die ermittelten Schwankungsbreiten der Augenlinsentrockengewichte bei Füchsen von 2 Monaten bis 2 Jahren an, die in einer graphischen Darstellung (Abb. 1) bis zum 8. Lebensjahr fortgeführt wird. In einer weiteren Graphik (Abb. 2) werden die Alterspyramiden nach Linsentrockengewicht und Zahnalter gegenübergestellt.

Notizen: Zusammenfassung Bei sechs Gemsen aus dem Aargauer Jura und dem Tösstock im Kanton Zürich wurden 18 Nematodenarten im Magen-Darmtrakt und 2 weitere Arten in der Lunge gefunden. Bei 2 von 5 Tieren lag ein Befall mitEimeria spp. vor, 3 von 4 Tieren waren mitSarcocystis sp. infiziert. Von 213 Gemslungen aus den Kantonen Appenzell-Innerrhoden, Schwyz und Luzern wiesen 114 Protostrongyliden- und 1 Dictyocaulus-Befall auf. Es wird festgestellt, daß bei der Trichostrongylidenfauna der Gemse weitreichend Überschneidungen mit den Artenspektren bei Schaf und Ziege, Rind, Reh und Rotwild bestehen.

Notizen: Zusammenfassung In den Jahren 1970–1972 wurden an 58 Schweizer Juragemsen (Rupicapra rupicapra [L.]) aus dem Raume Waldenburg — Olten — westlicher Weißenstein (Kantone Basel-Landschaft und Solothurn) und Chasseral (Kanton Bern) parasitologische Untersuchungen durchgeführt. Die untersuchten Tiere stammen alle aus Populationen, die auf Aussetzungen von Gemsen aus den Schweizeralpen zurückgehen. An Endoparasiten wurden drei Lungennematoden, acht Magen-Darmnematoden (teilweise nicht bis auf die Art differenziert), ein Trematode, zwei Cestoden und Coccidien nachgewiesen. Die Befallsextensitäten und-intensitäten wurden mit zwei Untersuchungen aus Österreich verglichen, im Falle der Lungenwürmer zusätzlich mit einer schweizerischen und einer deutschen Arbeit. Befallsintensität und-extensität scheinen im Bernerjura etwas geringer zu sein als im Baselbieter- und Solothurnerjura. An beiden Orten sind sie, teilweise sehr eindeutig, niedriger als in den Vergleichsgebieten der Alpen. (Ausnahme:Protostrongylus in den Kantonen Basel-Landschaft und Solothurn.) Aus der geringen Intensität und dem seltenen Auftreten von Fallwild wird geschlossen, daß die Kondition der Juragemsen gut ist. Das könnte auf Eignung des Juras als Gemshabitat und auf das Fehlen von Übervölkerungseffekten hinweisen. Die geringe Extensität läßt ebenfalls nicht überhöhte Dichte vermuten, zusätzlich einen für die freien Parasiten ungünstigen Biotop und einen geringen Einfluß des vorhandenen Kontaktes mit Haustieren. Das Artenspektrum liegt im Rahmen des zu Erwartenden.

Notizen: Zusammenfassung Es wird über einen Fall von Papillomatose im Bereich des Praeputium bei einem freilebenden Damhirsch berichtet.

Notizen: Zusammenfassung Es wird über eine Beobachtung von Fruchtmazeration in der Vagina beim Reh berichtet.

Notizen: Zusammenfassung Beschrieben wird die Ausbildung einer Knochenkapsel an der rechten Schädelhälfte eines Rehbockes, die vermutlich durch eine langsam wachsende Geschwulst entstanden ist.

Notizen: Zusammenfassung Bei 4 von 488 Füchsen aus dem Kanton Bern (Schweiz) fanden sich 5 Prämolaren im Unterkiefer mit einer dritten lateralen Wurzel (viermal bei P2, einmal bei P4). Zeit und Ort der Abschüsse weisen auf eine genetische Verbindung hin. Ökologische Aspekte werden diskutiert.

Notizen: Zusammenfassung Es wird ein Fund von 8 ExemplarenGoniodes sp. in der Federspule einer frisch gemauserten 10. Handschwinge eines Auerhahnes beschrieben (21. 5. 1972 Abb. 1, 2). Der Kot und die beschädigte Federseele sprechen für ein fakultatives Besiedeln dieses für die o. g. Gattung abnormalen Lebensraumes. Ein anderer unweit des ersten Fundortes erlegter Auerhahn hatte eine blutige Federseele in den zwei mittleren Stoßfedern und einer Armschwinge; bei einigen Larven und VollkerfenGoniodes sp. deutet die Farbe des Darmkanals auf Blutaufnahme (13. 5. 1973 Abb. 3, 4).

Notizen: Zusammenfassung An Hand von 4 Photos wird auf Ähnlichkeiten in der Gehörnform hingewiesen, die sich zum Teil nach Jahrzehnten auf engstem Raum wiederholten.

Notizen: Zusammenfassung An 25 Unterkiefern von Hasen wurden drei Meßwerte zum Längenwachstum des Unterkiefers, zum Längenwachstum des Zahnes und zum Breitenwachstum der Zahnhöhle auf ihre möglichen Abhängigkeiten zum Alter überprüft. Für eine exakten Nachweis der Altersabhängigkeit reichte das Material nicht aus, aber die hohe Wahrscheinlichkeit der Abhängigkeit konnte doch erhärtet werden. Durch diese Arbeit sollen größere Kreise veranlaßt werden, weiteres Kiefermaterial zu sammeln, um Abhängigkeiten nachweisen und zu einer Altersbestimmungsmethode ausbauen zu können.

Notizen: The NMEA GGA standard for global positioning system (GPS) and GLONASS receiver interfaces provides smooth data transfer from receiver to computer for postprocessing. Specifically, the NMEA GGA specifies that the orthometric height and the undulation be listed in addition to other quantities. The Ashtech manual (Ashtech, 1997; p. 104), however, specifies that the respective field in the NMEA GGA message contains the ellipsoidal height when outputting from Ashtech's GG24 receiver. Because such an inconsistency between the official NMEA GGA specifications and the implementation by a manufacturer can potentially confuse the user, we carried out a numerical test to confirm Ashtech's implentation. The result indicates that Ashtech indeed gives the ellipsoidal height in the fielt that should actually contain the orthometric height according to the NMEA GGA specifications. Firmware version after and including GF02 have corrected this situation. © 2000 John Wiley & Sons, Inc.

Notizen: In this article, analytic expressions are given for the minimal detectable biases (MDBs) of dual-frequency cross-correlated global positioning system (GPS) single difference code and carrier observations. They are given for three different short baseline models. (Short here implies that orbital and atmospheric uncertainties are assumed absent.) A comparison is made with the expressions for the MDBs of non-cross-correlating receivers. Finally, in order to get a better understanding of them, MDBs are visualized as a function of the parameters on which they depend, such as the number ob tracked satellites and the number of observation epochs. © 2000 John Wiley & Sons, Inc.

Notizen: As technology matures, Real Time Kinematic (RTK) global positioning system (GPS) receivers are providing increased performance in accuracy, on-the-fly (OTF) initialization times, measurement speed, and latency. Leica's Dozer 2000 machine guidance system combines an MC1000 GPS sensor, graphic intensive guidance software, a digital terrain model, and a digital site plan. Figure 1 shows the operator's view of the system. The end results is a highly accurate, extremely responsive local navigation system. Engineers can easily upload design information onto a touch-screen machine guidance personal computer (PC) and greatly reduce earthmoving costs while simultaneously recording “as-built” inspection data. The Leica MC1000 machine control sensor is a true 10-Hz, centimeter-level-accuracy, open-architecture GPS sensor specifically designed for machine guidance and control. At the heart of the MC1000's performance are a very stable oven-controlled oscillator (3 × 10−11/s short-term stability), a low-power Intel 486-DX4-80 processor, and four user-configurable input/output (I7O) ports. Special algorithms mitigate the effects of multipath and Selective Availability (SA) while providing centimeter accuracy up to 10 times per second with only 30 milliseconds' latency. The high update rate and low latency are essential for machine guidance and control. The MC1000 GPS reference station is capable of outputting RTK and Differential GPS (DGPS) data simultaneously, providing and entire site with GPS information for machine guidance and control, tracking and dispatching of vehicles, and support of survey crews. This article describes how recent advances in technology have combined to produce the Leica Dozer 2000 – a machine guidance system that is ideal for a wide range of earthmoving and inspection applications. © 2000 John Wiley & Sons, Inc.

Notizen: A global positioning system (GPS)-based online control and alarm system (GOCA) for monitoring of three-dimensional movements has been developed at the Karlsruhe University of Technology. The GOCA hardware consists of an array of GPS sensors and communication units to be placed in the monitoring area. The hardware-dependent control software communicates with the GPS sensors and provides the GPS baseline data and covariance information to the GOCA deformation analysis software. The GOCA center, which comprises both the control software and the GOCA software, may be linked – for example, over a long distance – to another personal computer (PC) that serves as a remote control station. GOCA is able to provide the full capabilities of classical deformation analysis online (with stations grouped into stable points and moving object points). Both types of points may be occupied either continuously or over short periods at different times. The object points are determined with respect to the stable points. A network adjustment is performed for each interval of data collection, and the coordinate and covariance information may optionally be transformed into a specific reference system (e. g., the building system). Unstable reference points are to be detected by statistical tests. The estimated object point time series are filtered with respect to gross errors using robust estimation techniques. Online filters are used to smooth the time series data of critical displacements and to predict other deformation functions. The time series data, as well as prediction results, are displayed graphically for each object point. An example concerning the online monitoring of a slag heap in a coal-mining area is included. © 2000 John Wiley & Sons, Inc.

Notizen: This article describes a single difference approach to estimate heading and pitch with a twin global positoning system (GPS)/GLONASS (GG) receiver system. Augmentation of GPS with GLONASS is not straightforward, however, because the latter system employs the frequency division multiple access technique to distinguish the signals form different satellites, rather than the code division multiple access technique used by GPS. The fact that each GLONASS signal has its own slightly different frequency makes the double difference (DD) of carrier phase observables no longer possible without modification. To get around this problem, the use of the between-receiver single difference (SD) of the carrier phase observables is proposed. In this case, however, receiver clock and other errors do not cancel out. The possibility of using a common external oscillator for the two receivers is explored. Remaining time and other biases are estimated using a low-pass averaging filter. The single difference integer ambiguities can then be resolved and the heading and pitch can be determined with a relatively good level of accuracy. Static and kinematic tests conducted with a pair of GPS/GLONASS receivers are used to validate the approach. Under reduced visibility, the combined GPS/GLONASS approach is shown to yield superior availability. © 2000 John Wiley & Sons, Inc.

Notizen: In June 1999, United States Space Command took formal steps to set up a support center for military and government Global Positioning System (GPS) users worldwide. The center was created to meet three main objectives: · Detect, analyze, report, and facilitate the resolution of GPS anomalies · Monitor and report GPS performance · Provide GPS status, constellation status, and tactical support This article is intended to provide a brief overview of the GPS Support Center (GSC), outlining its creation and products and services, and providing a more detailed discussion of its objectives. © 2000 John Wiley & Sons, Inc.

Notizen: The Internet as a basis for Real-Time Kinematic (RTK) and differential Global Positioning System (DGPS) service provides many advantages for worldwide GPS users. Among these advantages are service unification, open architecture, bidirectional communication, and scalability. The current development of this service allows users to use RTK and DGPS through the Internet with conventional accuracy over the short and medium baselines. The perspective for this service lies in the field of wide-area augmentation systems (WASS). At this stage of the Internet-based RTK and DGPS service project, the general concept, system components, draft standards, and software are developed. © 2000 John Wiley & Sons, Inc.

Notizen: In this article, the architecture of a software Global Positioning System (GPS) receiver is described and an analysis is included of the performance of a software GPS receiver when tracking the GPS signals in challenging environments. Results are included that demonstrate the advantage of the software GPS receiver in tracking the GPS signals in low signal-to-noise or jamming scenarios. Various current and previous applications of the software GPS receiver are also described. © 2000 John Wiley & Sons, Inc.

Notizen: Unlike the conventional hardware approaches to GPS base band signal processing, a software GPS receiver is extremely flexible as it comes with all the associated advantages of a software solution. With a software solution, the improvements of silicon technology can be easily translated into better performance at smaller form factors and lower power consumption, without a redesign and/or change to the ASIC. A general purpose Digital Signal Processor (DSP) can be used effectively for GPS signal processing. The memory and speed resources available determine the algorithms and applications that can be effectively implemented in the receiver. The performance of software GPS receivers will soon be difficult to be surpassed by the hardware counterparts, as high-performance processors become available at low cost. © 2000 John Wiley & Sons, Inc.

Notizen: This paper presents the current progress of the River Level Monitoring using GPS Heighting (RiGHt) project. The aim of the project is to develop an integrated system to allow the continuous monitoring of river heights using a buoy equipped with Global Positioning System (GPS) and satellite communications and using Geographical Information System (GIS) techniques. © 2000 John Wiley & Sons, Inc.

Notizen: Kinematic differential Global Positioning System (DGPS) positioning is routinely used in industry for directly observing an aircraft's position at each instant of photographic exposure during a photogammetric survey. A critical aspect of the subsequent data processing is estimation of the aircraft position at the exact time of exposure. GPS measurements are acquired at a uniform sampling rate, typically 1 Hz. The exposure times, however, do not generally coincide with these times. As a result, the exposure station positions must be interpolated from the adjacent GPS positions. This is typically done using a low-order polynomial, expressed as a function of time, for each coordinate dimension. However, trajectory perturbations induced by atmospheric turbulence can render such interpolation methods ineffective. This article will convey the results of an investigation into the use of several different interpolation models with airborne GPS data during straight, level flight. The fundamental task of time series reconstruction will first be addressed, in which several possible interpolation models are described. Two 10-Hz, airborne GPS data sets were collected to test the accuracy of each model. The error properties resulting from the application of each model to these data will be presented and analyzed in terms of time-domain statistics and frequency-domain characteristids. It will be demonstrated that interpolation error can be significantly reduced, especially in the height dimension, through judicious choice of an interpolator. © 2000 John Wiley & Sons, Inc.

Notizen: In recent years the importance of real-time positioning and navigation with the Global Positioning System (GPS) has grown rapidly. Starting from the establishment of differential GPS (DGPS) reference stations for marine and land navigation, new users and applications have emerged that resulted in a high demand for the establishment of a high-density network of reference stations around the world. Many countries have established their own DGPS service, which is either governmentally or commercially owned. These services are referred to as Local Area DGPS Systems (LADGPS). However, the costs for the establishment and maintenance of a dense network of reference stations are very high. Therefore Wide Area DGPS Systems (WADGPS) are being developed to overcome the main drawbacks of LADGPS. In this case, only a few reference stations are used to cover a large area, such s a continent like Europe. To achieve high positioning accuracies, real-time modeling of the main error sources for long-range baselines is required as errors in the satellite orbit and ionospheric refraction do not cancel entirely in double differencing. In this article, a real-time correction model based on the Kalman filter for WADGPS and networked LADGPS services is discussed and results of field tests in a WADGPS network in Europe are presented. © 2000 John Wiley & Sons, Inc.

Notizen: Abstract. We consider the problem of upscaling transient real gas flow through heterogeneous bounded reservoirs. One of the commonly used methods for deriving effective permeabilities is based on stochastic averaging of nonlinear flow equations. Such an approach, however, would require rather restrictive assumptions about pressure-dependent coefficients. Instead, we use Kirchhoff transformation to linearize the governing stochastic equations prior to their averaging. The linearized problem is similar to that used in stochastic analysis of groundwater flow. We discuss the effects of temporal localization of the nonlocal averaged Darcy's law, as well as boundary effects, on the upscaled gas permeability. Extension of the results obtained by means of small perturbation analysis to highly heterogeneous porous formations is also discussed.

Notizen: Abstract. Some of the considerable statistical content of modified Bessel functions of the second kind and of Tricomi's confluent hypergeometric function is illustrated. Moment solutions for the parameters of exponential class distribution functions based on both are derived. Unlike the generalised inverse Gaussian, the Tricomi exponential distribution is little known but it emerges that it is of wide applicability, highly flexible and has the gamma distribution as a special case.

Notizen: Abstract.  The use of complicated models of the cancer process has been limited by the need to have a mathematical framework allowing for a general expansion of the theory of carcinogenesis while maintaining numerically tractable results. A system of ordinary differential equations is derived for calculating tumor incidence in multistage models of carcinogenesis. The resulting system of equations is applicable to nonhomogenous processes (i.e. ones in which the rates change with time, age, etc.). In addition, a solution is given for the case of instantaneous initiation. These formulae can easily be coupled with physiologically-based pharmacokinetic models to link biomarkers of exposure to cancer risks. An example is presented.

Notizen: Abstract. In this study, we assess the risks of global warming on distributions of individual tree species in Switzerland. Applying a spatially explicit model, tree occurrence is predicted as a function of high resolution and physiologically relevant biophysical variables. The study shows that warming only slightly alters the overall abundance of tree species. However, the preferred temperature regimes are unevenly distributed along an elevational gradient, and the sensitivity to temperature varies considerably between the species. As a result, major reorganizations of forests in montane and subalpine belts are expected, i.e., a segregation of the core distributions of Fagus sylvatica and Picea abies is observed. Tree distribution potentials near timberlines, however, remain roughly the same.

Notizen: Abstract This study deals with the emission of methane in relation to changing environmental conditions and human impact, in three mangrove ecosystems of south India. Time-varying fluxes of methane adopting the close chamber technique were used to estimate CH4 emission from an unpolluted site (Pichavaram mangroves) and two polluted sites viz. (1) Ennore Creek mangroves (affected by fertilizer effluents and crude oil discharges) and (2) Adyar estuary mangroves (affected by the discharges of organic and industrial wastes), covering monthly and seasonal variations. The results indicate annual average CH4 emissions of 7.4, 5.02 and 15.4 mg m−2 h−1 from the sediment–water interface of the Pichavaram, Ennore Creek and Adyar estuary respectively. Emission characteristics obtained at Pichavaram mangroves represent a natural variability with changing physico-chemical factors, whereas the emission characteristics at Ennore Creek and Adyar estuary mangroves show anthropogenic influence. Several environmental factors such as oxygen availability, organic matter, soil physical and chemical properties, in addition to human-mediated interventions have been identified as influencing emission rates in the mangrove ecosystems. Preliminary CH4 emission estimates for the mangrove ecosystems along the Indian sub- continent and the tropical and subtropical coastline of the world by linear extrapolation based on surface area range from 0.05 to 0.37 and 2.8 to 19.25 Tg CH4 year−1 respectively. Our results also highlight the impact of human activities on future emission of methane from the mangrove ecosystems.

Notizen: Abstract. Environmental protection policies in the automobile market were not implemented until the motorisation of the masses in the 1960s caused an increasing environmental burden. The rising air pollution was considered a latent danger to humans, animals and plants. In the years up to 1985 the EU passed several regulations to limit the mass pollutants CO, CxHy and NOx. Germany was the first EU-member nation to also be concerned with lead in gasoline, passing reduction regulations as early as 1971. In 1986, several EU-member nations implemented the supply of unleaded gasoline. This decision was predominantly based on information about widespread forest damage. The reduction of lead emissions due to these regulations could be verified in different environmental systems. An example of this was the decline of atmospheric lead concentrations and human blood lead levels in Germany. With regard to industries, the German mineral oil and automobile markets were affected mostly. The price trend of gasoline was no longer only influenced by varying crude oil prices but also by tax discrimination between leaded and unleaded fuel. With regard to the distribution system, the market positions particularly of the medium-sized traders and the independent importers were weakened. In the automobile market, favourable terms of competition were experienced by producers who had already gained experience with catalyst systems in the US market. The Gasoline Lead Content Regulations had no significant effects on further economic indicators, except for competition.

Notizen: Zusammenfassung Eine statistisch signifikante Senkung des Cholesterinspiegels durch hohe Dosen Ascorbinsäure wird beim gesunden, normocholesterinämischen Menschen der mittleren Altersgruppe mit guter Ascorbinsäureversorgung gezeigt. Der Umfang der Cholesterinspiegelsenkung ist von der Vitamin-C-Dosis abhängig und um so deutlicher, je länger die Ascorbinsäure zugefÜhrt wird. Zusammenhänge zwischen Ascorbinsäurestatus und Arteriosklerose werden besprochen und Möglichkeiten zur Erklärung unterschiedlicher Literaturbefunde erläutert.

Notizen: Zusammenfassung Bei 231 Patienten wurden während der Infusionstherapie von sechs Tagen mit den Zuckern Xylit, Fructose und Glucose die Serumwerte fÜr Harnsäure, Bilirubin, anorganisches Phosphat, Harnstoff-Stickstoff und Gesamteiweiß beobachtet. Im einzelnen zeigen sich folgende Ergebnisse: 1. Xylit- und fructoseinduzierte Harnsäureanstiege konnten regelmäßig nachgewiesen werden. Die Maxima fanden sich am vierten bzw. am fÜnften und sechsten Tag nach Beginn der Infusionsbehandlung. Bereits während der Behandlung findet sich ein RÜckgang der mittleren Harnsäurekonzentration und nach Absetzen eine völlige Normalisierung. 2. Nach Infusion von Xylit und Fructose und deren Kombinationen erhöht sich vorÜbergehend die Bilirubinkonzentration. Die maximalen Anstiege werden nach Applikation von Xylit am zweiten und nach Infusion von Xylit und Fructose am vierten Tag gefunden. 3. Während der Infusionsbehandlung fanden sich bei 26% pathologische Werte fÜr das Serumphosphat. 25mal wurde eine Hyperphosphatämie und 26mal eine Hypophosphatämie beobachtet. 4. Die Harnstoff-Stickstoff-Konzentration im Serum zeigt eine Tendenz zur Verminderung. In 47 Fällen trat eine Hypoproteinämie auf, wobei der größte Abfall des Gesamteiweißes nach Xylit und Xylitkombinationen auftrat. 5. Bei Patienten mit Retention von Harnstoff-Stickstoff und Hyperurikämie fÜhrt die Infusionstherapie zu keinem weiteren Anstieg der Serumharnsäure. Jedoch wurde ein kontinuierlicher Anstieg des Harnstoff-Stickstoffs beobachtet.

Notizen: Zusammenfassung Dieses Gesetz soll vor allem für die Wiederherstellung, die Sicherung und Entwicklung der Leistungsfähigkeit des Naturhaushaltes und der Vielfalt der natürlichen Umwelt sorgen. Es wird ein wirksames Instrument zur Planung und Steuerung der Funktionsabläufe im komplexen Wirkungsgefüge der natürlichen Faktoren darstellen und dem Menschen einen höchstmöglichen Nutzen und damit verbunden ein höchstmögliches Wohlbefinden für viele Generationen bringen. Da dem Bund auf dem Gebiete des Naturschutzes und der Landschaftspflege bisher nur die Rahmengesetzgebungskompetenz zusteht, lassen sich die obengenannten Aufgaben jedoch nur durchführen, wenn ihm dafür die volle Gesetzgebungskompetenz übertragen wird. Damit würden auch verbesserte Voraussetzungen für die internationale Zusammenarbeit geschaffen werden. Die Nutzungsmöglichkeiten der Natur sind nicht unbegrenzt. Die anwachsende Erdbevölkerung und ihre zunehmenden Ansprüche machen die Grenze bewußt, an die wir stoßen oder die wir überschreiten, wenn wir unsere natürliche Umwelt nicht haushälterisch bewirtschaften, also Umweltvorsorge nach ökologischen Kriterien im Sinne von Naturschutz und Landschaftspfiege treiben. Die Aufgabe der qualitativen Gestaltung unserer natürlichen Umwelt ist nicht länderweise, kaum national, nur weltweit zu lösen. Auch der Europarat und die Vereinten Nationen haben die Völker Europas aufgerufen, gegen die zunehmende Zerstörung der Natur aktiv vorzugehen. Diesem Ruf sind in der Bundesrepublik Deutschland Bund und Länder, Städte und Gemeinden, insbesondere auch der Deutsche Naturschutzring und die ihm angeschlossenen Verbände gefolgt. Ihnen ist es gelungen, den Naturschutzgedanken wieder volkstümlich zu machen. Der Schutz der Natur ist eine Aufgabe, die alle Bürger angeht und bei der alle Bürger mithelfen können und müssen. „Jeder einzelne sollte erkennen“, so heißt es in der Europäischen Naturschutzdeklaration, „daß von seinem Interesse und seinem Engagement als Bürger die Erfüllung seiner berechtigten Wünsche nach einer besseren Umwelt abhängt“.

Notizen: Zusammenfassung Der Aminosäuregehalt des Baladi-Brotes wurde bestimmt, um den Mangel an bestimmten essentiellen Aminosäuren abzustellen. Gemessen am „provisional pattern“ der FAO, hat das Brotprotein einen FAO-Protein-Score von 61. Die limitierenden essentiellen Aminosäuren Lysin und Threonin wurden dann in freier Form zu Baladi-Brot-Diäten zugelegt, in denen das Baladi-Brot-Protein 10% der Diät ausmachte. Die Ergänzung des Baladi-Brotes mit 0,24 % L-Lysinhydrochlorid; 0,088 % DL-Threonin und 0,50 % DL-Methionin erwies sich am besten und erhöhte die „protein efficiency ratio“ des Proteins auf einen Wert von 3,31, verglichen mit einem Wert von 1,28 für Baladi-Brot-Protein mit Methioninzulage allein.

Notizen: Zusammenfassung Mit dem ungarischen Chlorphentermin-Präparat Desopimon haben wir bei 20 Personen Entfettungskuren ausgeführt. Mit dem standardisierten Kaliber wurde an zehn Körperstellen die Hautfaltengrößen bestimmt. An Hand der Hautfaltengrößen ist die mengenmäßige Abnahme des Körperfettes gut zu verfolgen. Es wurde festgestellt, daß praktisch nur das Körperfett infolge der Entfettungskur abnimmt; eine gewisse Verminderung findet aber auch bei den anderen Körperelementen statt.

Notizen: Summary Background: The knowledge of magnesium requirements of premature infants is still very limited, although it is essential for the optimal composition of suitable formulas. Aim of the study: The study concept was 1) to assess physiological magnesium balance data of healthy term infants and longitudinal results from formula-fed premature infants and 2) to deduce conclusions on the magnesium content of the formulas. Methods: Premature infants (n = 14, birth weight ≤ 1500 g, gestational age ≤ 32 weeks) were studied in conventional balance trials with 1) a semi-elemental diet (A), 2) preterm infant formula (B), and 3) infant formula (C). In addition, healthy term formula-fed (n = 11, D) and breast-fed (n = 14, E) infants were investigated. Analysis was performed by flame atomic absorption spectroscopy. Results: The median magnesium intake ranged between 4.84 mg/kg × d−1 (breast-fed infants) and 16.33 mg/kg × d−1 (premature infants). The term breast-fed infants retained nearly as much magnesium as term formula-fed infants (3.37 vs. 3.97 mg/kg × d−1), due to a low percental fecal and urinary excretion. A higher magnesium retention was observed in the premature group: A: 7.97 mg/kg × d−1, B. 5.3 mg/kg × d−1, 3.) 5.54 mg/kg × d−1. Conclusion: In view of the high percental magnesium retention in formula-fed premature infants, excessive supply should be avoided. The long-term effects of lower intakes have to be monitored.

Notizen: Summary We reviewed 15 studies reporting on the fatty acid composition of colostrum lipids from 16 geographic regions: 11 European studies and one study each from Central America, the Caribbean, Australia and Asia. The contents of essential fatty acids, saturates and polyunsaturates were similar in the southern European countries Spain, Slovenia and France. Colostrum of St. Lucian women was high in saturates and low in oleic acid, reflecting a high-carbohydrate, low-fat diet. Abundant fish intake was reflected in high contents of docosahexaenoic acid and total n-3 long-chain polyunsaturated fatty acids in St. Lucia. Two French studies published with an interval of two years showed a very similar colostrum fatty acid composition, whereas two German studies obtained with an interval of 14 years showed higher docosahexaenoic acid and arachidonic acid contents in the later study, with an unchanged n-6/n-3 long-chain polyunsaturated fatty acid ratio. Studies from Spain reported a decline of α-linolenic acid in colostrum over a time period of 13 years. Colostrum of Australian women contained the lowest polyunsaturated/saturated and n-6/n-3 long-chain polyunsaturated fatty acids ratios (0.28 and 1.58) and the lowest contents of linoleic and α-linolenic acids (7.8 and 0.4 wt. %). In contrast, the contents of docosahexaenoic acid, eicosapentaenoic acid and total n-3 long-chain polyunsaturated fatty acids (0.6, 0.4 and 1.4 wt. %) were higher in Australian than in European samples. Fatty acid composition of human colostrum appears to be markedly influenced by geographic differences in maternal dietary composition.

Notizen: Summary The metabolic strengths, weakness, opportunities and threats of the metabolic ability to split water brought about a proliferation of biological systems, produced a toxic oxygenic environment, and were responsible for the development of antioxidant defence mechanisms. Evolution is driven by heritable adaptions which improve environmental ‘fit’. Hence aerobic respiration, using oxygen as a nutrient, came to predominate in biological systems, and antioxidant defence mechanisms which prevent and neutralise toxic oxygen intermediates have become widespread, varied, coordinated and effective. Antioxidant defences are nor infallible however. In humans, reactive oxygen species-induced damage is associated with the ageing process, and with chronic diseases including cancer and coronary heart disease. Interestingly, some important antioxidants, including ascorbic acid and the tocopherols, cannot be synthesised by humans and must be taen in the diet. Another antioxidant, uric acid, is found in much higher concentrations in humans than in other mammals, and levels are also affected by diet. In humans, therefore, antioxidant defence against toxic oxygen intermediates is species specific and heavily influenced by nutrition. In this article, the atmospheric and metabolic changes which produced both the threat and opportunity offered by an oxygenic environment are outlined. An overview of oxygen toxicity, and adaptations to oxidative stress in terms of evolution of antioxidant defences, is presented. Finally, suggested benefits underlying our curious inability to manufacture ascorbic acid, and the possible role of uric acid in human antioxidant defence, are briefly discussed with particular reference to nutrition and toxicology.

Notizen: Summary Background: Many epidemiological studies have identified a protection against cancer associated with consumption of fruit and vegetables. One factor is this protection may be the enhancement of cellular DNA repair activity by micronutrients, such as carotenoids, found in these foods. Aims of the study: To measure the capacity of lymphocytes isolated from volunteers supplemented with β-carotene, lutein or lycopene to recover from DNA damage induced in vivo by treatment with H2O2. Methods: Healthy volunteers were given supplements of lutein (15 mg/day), lycopene (15 mg/day) and βcarotene (15 mg/day), each for 1 week, the supplementation periods being separated by 3-week wash-out periods. Blood samples were taken at the beginning and end of each supplementation, and at 1 week and 3 weeks during the wash-out period. Carotenoid levels were measured in plasma. Lymphocytes were isolated and frozen. Subsequently, they were treated with 100 μM H2O2 and incubated for up to 24 h; DNA damage was measured with the comet assay (single cell gel electrophoresis) after 0, 2, 4, 8, and 24 h. Results: Increases of 2- to 3-fold in mean plasma lutein and β-carotene concentrations were seen at the end of the respective supplementation periods; they returned virtually to basal levels after wash-out. Lycopene concentrations were less affected by supplementation, and were more variable. H2O2-induced DNA strand breaks were apparently only slowly rejoined by the lymphocytes. The rejoining of breaks in the first few hours appeared substantially faster in lymphocytes following supplementation with β-carotene, but no such effect was seen with lutein. In those individuals who showed increases in lycopene concentrations, the recovery was significantly faster. Lymphocytes that were not treated with H2O2 showed a transient increase in DNA breakage to about double the background level in 2 h, presumably as a result of exposure to atmospheric oxygen; this effect, too, was relieved by supplementation with lycopene or β-carotene. Conclusions: While certain carotenoids appear to enhance recovery from oxidative damage, this is probably in fact an antioxidant protective effect against additional damage induced by atmospheric oxygen, rather than a stimulation of DNA repair.

Notizen: Summary Obesity could well become the most common health problem of the 21st century. There are more opportunities to consume large quantities of food: big portions of tasty, varied food, at reasonable prices, are available everywhere. Moreover, our bodies are better adapted to combat weight loss than to combat weight gain, since for thousands of years our species evolved in circumstances where nutrients were in short supply. The response of each individual to diet and other environmental factors varies considerably, depending on the characteristics of his/her body weight control mechanism. The differentiating element in the future, especially as regards the dietary and pharmacological control of obesity, will be knowledge of an individual's possible response depending on his/her genetic background. Obesity can occur as a result of genetic or acquired changes in three main types of biochemical processes, which are the main focus of this review: a) feeding control, which determines the sensations of satiety and hunger through processes that depend on a interplay between internal signals (notably leptin) and environmental factors; b) energy efficiency, in particular the activation of thermogenesis mediated by uncoupling proteins (UCPs) that makes it possible to dissipate part of the energy contained in food as heat instead of accumulating it as fat, and c) adipogenesis, the process by which cells specialised in fat storage (adipocytes) are formed, which is controlled by an interplay of transcription factors, including memebers of the C/EBP, PPARγ and ADD families. The knowledge of a growing numbers of genes and molecules implicated in these three types of processes and of their metabolic relationships is leading toward a molecular understanding of the body weight regulatory system and is paving the way for new methods of obesity control, especially pharmacological but also nutritional and possibly involving genetic intervention.

Notizen: Summary Background: Quantitative information on conversion of β-carotene to vitamin A in humans is limited. Aim of the study: Our laboratory has developed a stable isotope method for studying the conversion of β-carotene (β-C) to vitamin A. Methods: Two dosage levels (a pharmacological dose, 126.0 mg β-C-d 8, and a physiological dose, 6.0 mg β-D-d 8) were used 2.5 y apart in an adult female volunteer to study dose effects on the conversation of β-C to vitamin A. Blood samples were collected over 21 d. β-C and retinol were extracted from serum and isolated by high performance liquid chromatography. The retinol fraction was derivatized to a trimethylsilyl ether which was analyzed by gas chromatograph/mass spectrometry with electron capture negative chemical ionization. Results: The retinol-d 4 response in the circulation peaked at 24 hours after the β-C-d 8 dose, with a higher percent enrichment after the pharmacological dose than after the physiological dose. By using retinyl acetate-d 8 as the vitamin A reference, the retinol-d 4 formed from 6 mg of β-C-d 8 (11.2 μmol) was calculated to be equivalent to 1.6 mg of retinol (i. e., 3.8 mg of β-C was equivalent to 1 mg of retinol). However, the retinol-d 4 formed from 126 mg of β-C-d 8 (235 μmol) was equivalent to 2.3 mg of retinol (i. e., 55 mg β-C was equivalent to 1 mg retinol). Conclusion: These results provide evidence that it is feasibile to use stable isotope reference method to study retinol equivalence of β-C and that there may be a dose-dependence on bioconversion of β-carotene to retinol.

Notizen: Summary The potsitive effect of glutamine on lymphocyte proliferation has previously been described. Its dipeptide glycyl-glutamine (GlyGln) is more stable than pure glutamine in aqueous solutions. The aim of our study was to investigate the relationship between lymphocyte proliferation and varying concentrations of glycyl-glutamine in vitro. Isolated human lymphocytes were stimulated with the mitogens phytohaemagglutinin (PHA), Concanavalin A (ConA), pokeweed mitogen (PWM), and Staphylococcus aureus (SAC). Glycyl-glutamine was added to yield final cincentrations of 0–2 mmol/l. Overall minimal concentrations of 0.01 mmol/l glycyl-glutamine were sufficient to enhance lymphocyte proliferation over baseline (glutamine-free) levels. No difference was found between concentrations in the “physiological” range of 0.4 mmol/l and very low concentrations (0.04–0.1 mmol/l) with SAC, ConA and PWM. Increasing the concentration beyond 0.4 mmol/l (up to 2.0 mmol/l) offered further gain with PHA-stimulation only. Lymphocyte proliferation under in vitro polyclonal stimulation is maintained even at very low concentrations of glycyl-glutamine. Raising the concentration above the equivalent of physiological levels does not seem to provide further benefit.

Notizen: Summary Aim of the study. An allergen-reduced dietary intervention programme with strict dietary requirements was implemented over the first four months of life in an unselected population-based infant cohort and compared to a non-intervention cohort (the ZUFF study). Recommendations for the dietary programme in the intervention cohort were extended, but not strictly implemented, until the end of month six. The intervention was based on breastfeeding, a moderate whey hydrolysate formula (pHF), and delayed introduction of weaning foods with a high allergenicity. This study was a prospective, controlled, and unblinded study, the first to assess the effects of an allergen-reduced, pHF-based early nutritional programme in a broad unselected infant population. Because overall healthy development of the infant is a major objective of any nutritional programme, the study evaluated the effects of the dietary intervention on infant growth and general health status rather than specific allergic manifestations. Part I of this paper gave results for nutritional behaviour only, and Part II gives results for growth and general health status during the intervention period through the sixth month of life. Methods. Assignment of study infants was to demographically comparable intervention (Z) or control (FF) cohorts according to place of birth. In the intervention cohort (Z=564), the recommended dietary regimen was breastfeeding and – if exclusive breastfeeding was not possible – supplementation with a moderately hydrolysed, allergen-reduced infant formula (pHF). Weaning foods were delayed until four months of age or later in case of weaning foods with high allergenicity. In the control cohort (FF=566), there was no specific intervention. Imbalances between cohorts in confounding (adjuvant) factors that could influence health related outcomes were integrated as covariates into the logistic regression of the main analyses. Growth parameters included weight, length, head circumference, BMI, and Z scores (SDS). General health status was assessed by clinically significant findings in gastrointestinal, respiratory, or skin symptoms. Results. Growth at 6 weeks and at 3 and 6 months was similar for Z and FF. Significantly fewer Z than FF infants had clinically noteworthy health findings at 3 months (Z=27% versus FF=37%, odds ratio=0.63, CI=0.48–0.82) and 6 months (Z=33% versus FF=49%, odds ratio=0.51, CI=0.40–0.66). This corresponds to a 30% reduction in overall health concerns at 6 months for the intervention cohort. At 3 and 6 months, differences between cohorts in most measures of general health status were strongly influenced by a lower incidence of skin symptoms in the Z cohort. Within FF, there were fewer exclusively breastfed (eBF) infants with health problems at 3 months compared with those who were partially (pBF) or non-breastfed (nBF) (eBF=31%, pBF=40%, nBF=39%, p〈0.05). In contrast, in the Z intervention cohort, the number of infants with health concerns was similar for exclusively breastfed infants and for those in whom mother's milk was supplemented or replaced by pHF (eBF=29%, pBF=25%, nBF=26%, ns). In a subanalysis of overall health findings in infants without a family risk of allergies, there were again significantly fewer Z than FF infants with any health or any skin problem. Conclusion.An allergen-reduced dietary recommendation that includes a moderate whey hydrolysate infant formula (pHF) has no negative effects on growth parameters up to 6 months of life in an infant population unselected for atopic risk. The dietary intervention produced improvements in general health status when compared with a control cohort that received infant formula with unhydrolysed proteins (IF), and high allergenic weaning foods at an earlier age. The difference between cohorts was principally due to fewer adverse skin findings. In infants following our allergen-reduced feeding recommendation, 3-month general health status was comparable between those who were exclusively breastfed and those in whom breastfeeding was supplemented or replaced by pHF. Our results demonstrate that a pHF feeding recommendation during the first 4 to 6 months of life – when exclusive breestfeeding is not possible – is a safe and feasible regimen not only in high-allergic risk populations but in general unselected infant population. The general use of pHF formula in non- or partly breastfed infants could therefore be considered an important contribution to optimised infant nutrition.

Notizen: Summary Background: The dietary supplementation with EPA (eicosapentaenoic adic; 20:5n3) and DHA (docosahexaenoic acid; 22:6n3) has been recommended because of their favourable effects on the cardiovascular system (including complications of NIDDM). Oleic acid (18:1n9) from olive oil has some analogous and complementary effects. Potential competitive relations between long-chain n-3 fatty acids (FAs) and the oleic acid would therefore mean a problem. Aim of the study: We focused primarily on the oleic acid changes in serum phospholipids (SPL) after a supplementation with EPA and DHA. Methods: Thirty-five patients with type 2 diabetes mellitus (NIDDM) were supplemented for 28 days with 1.7 g of EPA plus 1.15 g of DHA/day (as Maxepa® capsules, Seven Seas®, U. K.). After that, a 3-month wash-out control period with 21 patients followed. A fatty acid composition of serum phospholipids (SPL) was determined by capillary gas-chromatography. Values were calculated as relative percentages of all FAs. Results: After the supplementation with the Maxepa® capsules, there was a very strong increase in EPA, docosapentaenoic acid (22:5n3) and DHA content in SPL. It was followed by a stron decrease after the wash-out (all p〈0.0001). The oleic acid SPL content after the intervention significantly decreased from 10.105±0.307% (mean ±S.E.M.) to 9.082±0.276% (p〈0.0003). During the wash-out, the change was in the opposite direction (p〈0.0001). When the intervention and the wash-out periods were taken together, changes in the oleic acid were inversely correlated with changes in EPA, docosapentaenoic acid and DHA (r = −0.729; r = −0.552; r = −0.629, respectively; p〈0.0001; n = 56). On the background of the overall n-6 FA reduction, the decline in the arachidonic acid after the supplementation (p〈0.0001) and its rise after the wash-out (p〈0.0003) were similar. There were no significant changes in the saturared FA spectrum. Conclusions: Supplementation with long-chain n-3 FAs in NIDDM patients leads to the lowering of oleic acid SPL content. Whereas the reduction of the arachidonic acid may have some desirable aspects (e. g. suppression of thromboxane TxA2 or 4 series leukotriene production), the decline of the former is to be regarded as a potential problem. Therefore, the search for optimally balanced blends of n-3 polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs) seems to be more promising than a supplementation with only one type of FA.

Notizen: Summary Background Present animal models used to emulate type 2 diabetes may not accurately reflect the metabolic changes that occur in humans. Aims of the study The purpose of this research was to evaluate diets reported to induce insulin resistance and impaired glucose metabolism in rats as a potentially useful model for studying type 2 diabets. Methods Three groups of male Sprague Dawley rats (n=7) were fed either a control diet, based on AIN recommendations (53% cornstarch, 10% sucrose and 7% soybean oil), a high fat diet (25% soybean oil, 35% cornstarch) or a high fructose diet (53% fructose, 10% sucrose) for a 3 month period. Glucose tolerance tests were carried out in week 3 and week 9 of the experiment. At the termination of the experiment, serum insulin, glucose, cholesterol and triacylglycerols were measured. Glucose incorporation into glycogen and glycogen synthase activity were measured in soleus muscles. Results Similar weight gain was observed for all three groups of rats. Glucose tolerance curves and fasting glucose levels were not significantly different at any time point in the experiment. Insulin levels were unchanged for the controls (171±21 pM), high fructose (164±16 pM) and high fat (181±30 pM) diets. Fasting serum triacylglycerols and cholesterol levels were not significantly elevated by dietary treatment. In soleus muscles, rats on all three diets had a significant increase in glycogen synthesis in response to insulin, but synthesis was similar in all three groups. Glycogen synthase activity was also not significantly affected by long-term dietary intervention. Conclusions In this study, healthy Sprague Dawley rats fed high fat or high fructose diets for 3 months adapted to the nutritional intervention without developing classical signs of insulin resistance and impaired glucose tolerance.

Notizen: Summary Background Bone mineral density (BMD) is largely genetically determined and this influence is most powerful in the period of rapid skeletal development in childhood and late adolescence but environmental factors such as exercise and dietary calcium intake may influence up to 20%. Aims of the study The aims of the study were to examine healthy late adolescent females for the effects and benefits of a high calcium intake from dairy product foods on bone mineral density, body composition, lipids and biochemistry. The secondary aim is determine whether a high intake of dairy product foods in the diet is acceptable for this age group long term. Methods Ninety-one teenage girls who participated in a two-year randomised controlled study on the effect of dairy food supplementation on dietary patterns, body composition and bone density in post-pubertal teenage girls were approached one year after the cessation of the study to determine the effects of the cessation of dairy supplements on bone mineral density, dietary habits, biochemical markers, body composition and blood lipids. Bone mineral density and bone mineral content were assessed at the hip, spine and total body. Anthropometric data were collected, and exercise, Tanner, dietary assessment, preference and compliance questionnaires were administered. Lipid profiles, hydroxyproline excretion and urinary calcium and sodium excretion measurements were performed. Results There were no significant differences between the 2 groups for height, weight, lean and fat mass. The supplemented group had significantly higher calcium, phosphorus and protein intake during the supplementation period (p〈0.001). No differences were seen between the groups 12 months after supplementation finished. There were no significant differences in exercise level, preference or acceptability of dairy products or in the lipids and bone markers between baseline the end of supplementation and 1 year follow-up. There was a significant increase in trochanter (4.6%), lumbar spine (1.5%) and femoral neck (4.8%) BMD (p〈0.05) in the high calcium group at the end of supplementation. There was an increase in bone mineral content at the trochanter (p〈0.05) and lumbar spine; however the latter was not statistically significant, in the high calcium group at the end of supplementation. There was no difference in vertebral height or width at any stage of the study, indicating no influence on bone size. Conclusions In this 3 year study (2 years of supplementation, 1 year follow-up), teenage girls, aged 15–18 years, were able to significantly increase their BMD at the trochanter, femoral neck and lumbar spine when supplemented with dairy product foods to a mean calcium intake of 1160 mg/d. There was also an effect seen on the BMC particularly at the trochanter and to a lesser extent at the lumbar spine. The dietary calcium intake achieved did not adversely affect body weight, fat and lean mass or blood lipid profiles. Twelve months after the supplementation finished the girls had returned to their baseline diet, indicating self-selection of a high dairy product diet may be hard to achieve.

Notizen: Abstract  This paper provides an analysis of pollution prevention, treatment and cure with respect to solvent-based processes. It is postulated that, in new processes, considering environmental constraints in the early stages of process design can prevent pollution due to inefficient recovery of solvents or inefficient separation by solvents. Pollution in existing processes can also be prevented through early treatment that includes assessment of causes and effects of future changes in process conditions and/or environmental regulations. Pollution cure is more difficult, since the process is already violating some environmental constraints and any solution also needs to satisfy social and economic constraints. A technique for pollution prevention, treatment and cure that is based on the use of computer-aided tools is presented. Application of the technique is illustrated through a case study that highlights the important steps of the solution approach and serves as a proof of concept.

Notizen: Abstract  A process was developed for the recovery of both arsenic and gallium from gallium arsenide polishing wastes. The economics associated with the current disposal techniques utilizing ferric hydroxide precipitation dictate that sequential recovery of toxic arsenic and valuable gallium, with subsequent purification and in-house reuse of both, is to the benefit of the gallium arsenide crystal grower. The developed process involves first the removal of the majority of the arsenic and suspended polish as a mixed precipitate of calcium arsenate and polish. This first process step is performed at ambient temperatures and at a pH〉11 using NaOH. At these pH regimes, gallium is retained in solution as a sodium gallate species. Precipitation of virtually pure gallium hydroxide is then accomplished in the next process step through pH adjustment to between 6 and 8 with waste acids. The commonly used ferric hydroxide coprecipitation step is retained as a final treatment step, but because of the removal of the majority of the arsenic, gallium, and polish in the two prior steps, far less waste is land disposed. A patent application has been filed with the United States Patent Office.