bluuebunny/crossref_metadata_2025 huggingface dataset:
Actuality and Obsolescence of Scientific Literature
Authors: Avramescu Aurel
Published: July 2010

In order to explain the much increased citation frequency of recently published articles in respect to the normal exponential decay of older articles, the scientific information diffusion theory is used. The obsolescence rate results by combining the Gaussian normal distribution with the exponentially decreasing rate of the number of, articles with age. For recently published works supplementary adjustments are necessary: first, in order to have the citation number start at zero at the start of counting, and second, in order to reach the sixfold citation climax two years before it. All peculiarities exhibited by experimental survey data have been properly reproduced by making plausible assumptions suggested by the diffusion theory, such as preference of virtual authors to directly read recent articles, preference for verbal cross‐communication with colleagues, and increased preference for the newest articles in fields of personal interest. The latter preference is damped in the case of older articles since virtual authors prefer to consult the scientific community or review books. The results do confirm once more the reliability of the scientific information diffusion model.
Using An INS Simulation to Forecast Manpower Needs
Authors: Mansfield Jerry W.
Published: July 2010

A simulation language is presented which lends itself to the modeling of library operations. Here a circulation department of a university library is modeled using Integrated Network System (INS) language. The public demands on the resources are measured as are a 10 and 20% increase in the demand. The resulting data are used by management to determine the efficiency of a network and to predict manpower needs.
The Theoretical Foundation of Zipf's Law and Its Application to the Bibliographic Database Environment
Authors: Fedorowicz Jane
Published: July 2010

What does the frequency of occurrence of different words in an article have to do with the number of times an article is cited? Or, for that matter, with the number of publications an author has? All of these—word frequency, citation frequency, and publication frequency‐obey an ubiquitous distribution called Zipf's law. Zipf's law applies as well to such diverse subjects as income distribution, firm size, and biological genera and species. Zipf in 1949 described a hyperbolic rank‐frequency word distribution, which he fitted to a number of texts. He stated that if all unique words in a text are arranged (or ranked) in order of decreasing frequency of occurrence, the product of frequency times rank yields a constant which is approximately equal for all words in a text. The law has been shown to encompass many natural phenomena, and is equivalent to the distributions of Yule, Lotka, Pareto, Bradford, and Price. An ubiquitous empirical regularity suggests some universal principal. This article examines a number of theoretical derivations of the law, in order to show the relationship between the many attempts at ascertaining a theoretical justification for the phenomenon. We then briefly examine some of the ramifications of applying the law to the bibliographic database environment.
An Evolutionary Approach in Information Systems Science
Authors: Stanoulov Nicolay
Published: July 2010

This article is concerned with a layout of methodological apparatus revealing the logical transition of information theory from one kind to another, creating from the existing information theory (i.e., informal theory) (i) a near‐formal information‐theoretic axiomatic system and (ii) an information metatheory (only briefly sketched here). The most outstanding example manifesting such an evolution (“optimization”) in the methodology of natural sciences is the transition of mathematics to meta‐mathematics. The significance of this approach lies in defining the subject matter to be studied, as well as in explicating its feature, and possibly forecasting new ones. Based on this knowledge an attempt to reconstruct a known model of scientific evolution of S. Watanabe is made. The modification of this model is “case‐oriented,” i.e., it depends on the mentioned metatheoretical reasons. The evolution of the information systems science via such a dynamical tool as the metatheoretical approach is grounded most generally in the developed informal theory confronted with the human and social needs.
Measurement of the Potential Demand for Academic and Professional Journals: A Methodology
Authors: Mcdonough Carol C.
Published: July 2010

This article proposes a methodology for measuring the potential demand for individual journals within an academic discipline and illustrates this methodology with data from the economics journals market. The impact of potential demand on journal circulation is then investigated by developing a model of journal demand that includes potential demand as an explanatory variable. The model is estimated with data from the economics journals market.
Information Research Management in Poland
Authors: Faber Roman F. , Murastkiewicz Mieczyslaw M. , Nowicki Zbigniew M.
Published: July 2010

This article describes the structure of the Polish information network and the concept of a national system of scientific and technical information. Attention is paid to information research management and the presentation of current results. The approach to research management and some results may be of interest to Western information officers and scientific workers because of two main factors: the nationwide scope of the system and its conceptual uniqueness.
Oil production: A probabilistic model of the Hubbert curve
Authors: Michel Bertrand
Published: July 2010

The specific distribution of hydrocarbon field sizes has a deep impact on the dynamics of the production inside a basin. This paper proposes a probabilistic model based on the field size distribution, taking into account the launching production process of the fields. This model can be seen as a ‘bottom‐up’ probabilistic method to simulate and predict oil production. The asymptotic results obtained allow us to propose relevant fitting to real production curves. Copyright © 2010 John Wiley & Sons, Ltd.
Polarimetrische und kolorimetrische Untersuchungen am Crab‐Nebel I. Polarisationsuntersuchungen
Authors: BöRNGEN F. , Chatschikjan E.
Published: July 2010

Es wird eine Polarisationsuntersuchung im blauen Spektralbereich am Crab‐Nebel durchgeführt. Das Beobachtungsmaterial wurde Ende 1962 mit der Schmidt‐Kamera des Tautenburger 2 m‐Spiegels gewonnen. Die Größe des Diaphragmas beträgt 5 × 5. Die Ergebnisse werden in einer auf das Nebelbild projizierten Zeichnung festgehalten.
Dreifarben‐Photometrie von NGC 5316
Authors: Rahim Mohamed Abdel
Published: July 2010

Von 130 Sternen im Gebiet des Offenen Haufens NGC 5316 (in Cen) wurde mit Beobachtungsmaterial vom Boyden‐Observatorium eine kombinierte photoelektrisch‐photographische Photometrie durchgeführt. Die Verfärbung ergab sich zu E(B—V) = 0.18, die Entfernung zu 1120 parsec. Der Haufen liegt damit an der Außenseite des uns benachbarten nächstinneren Spiralarms. Bis zur absoluten Größe + 4.8 enthält er 68 Hauptreihensterne und 5 Rote Riesen.
Die photometrische Genauigkeit des Palomar Sky Survey bei Anwendung der Durchmessermethode
Authors: Dorschner J. , GürTLER J. , Schielicke R. , Schmidt K.‐H.
Published: July 2010

An einem Material von 39 lichtelektrisch vermessenen Sternhaufen und einer Assoziation wurden Helligkeiten nach einer rationellen Durchmessermethode bestimmt. Die dabei erreichte Genauigkeit wird diskutiert.
Beobachtungen der RR Lyrae‐Sterne UY Camelopardalis und Y Leonis Minoris
Authors: Beyer M.
Published: July 2010

Für die wenig bekannten RR Lyrae‐Sterne UY Cam und Y LMi werden aus zahlreichen visuellen Einzelbeobachtungen in den Jahren 194665 abschnittsweise mittlere Lichtkurven abgeleitet, deren Eigenschaften Aufschlüsse über Veränderungen ihrer Gestalt, Helligkeitsamplituden und Perioden liefern.
Perioden‐Helligkeits‐Beziehungen von RR Lyrae‐Sternen in kugelförmigen Sternhaufen
Authors: Lohmann W.
Published: July 2010

Aus dem bis heute vorliegenden Beobachtungsmaterial ergeben sich für die RR Lyrae‐Sterne in etwa einem Dutzend kugelförmiger Sternhaufen (wenigstens andeutungsweise) verschiedene Perioden‐Helligkeitsbeziehungen, die aber nicht so ausgeprägt sind, wie für galaktische Sterne dieses Types.
Photographische Doppelsternmessungen mit Okularprojektion
Authors: Heintz W. D.
Published: July 2010

Aus Aufnahmen in den Jahren 1959–62 wurden Örter von 48 Doppelsternen erhalten; sie geben einen Überblick über die Anwendbarkeit der Vergrößerungsmethode.
Investigations on Type III/V Bursts of Solar Radio Emission. Part I: Phenomenology and Properties of Type V Bursts
Authors: Daene H. , KrüGER A.
Published: July 2010

The phenomenological features of type V radiation are discussed at the basis of fine structure records taken at the Astrophysical Observatory Potsdam since 1958. A phenomenological subclassification is derived from the various forms of appearance. It is believed that significant qualities are only the longer duration than that of normal type III bursts and the fact that nearly always a type III burst is preceding. It seems that there are no urgent reasons to consider type V emission as continuum radiation. It is assumed that no different excitation mechanism is effective for type III and type V. The observational facts are tentatively explainable by special assumptions about the structure of the exciting electron stream. Additionally it is taken into consideration that the prolonged duration of type V is due to a merging process. It is suggested that merging occurs if the same coronal area is reexcited by a second electron stream, whereas superposition occurs if different areas are excited by both the streams. The possibility is considered that harmonics partly contribute to the observed features.
Empirische Entscheidungsmöglichkeiten über die Natur quasistellarer Objekte
Authors: Barnothy J. M.
Published: July 2010

Es wird auf empirische Prüfungsmöglichkeiten hingewiesen, die zu entscheiden gestatten, ob Quasistellare Quellen überhelle Objekte oder durch Gravitationslinsen hervorgerufene Bilder sind.
Mitteilungen über neuentdeckte Veränderliche Sterne
Authors: Hoffmeister C.
Published: July 2010

The discovery of this list's 351 new variables was announced in Mitteilungen über Veränderliche Sterne. Here some more details are given, including epochs for short period and eclipsing variables and charts of the surroundings.
Bemerkungen zum Problem der Temperaturstrahlung bei Feuerkugeln
Authors: Oleak H.
Published: July 2010

Einige Zustandsgrößen, wie Temperatur, mittleres Molekulargewicht und Elektronenkonzentration werden unter der Bedingung thermodynamischen Gleichgewichts für die im Verdichtungsstoß aufgestaute Luft abgeleitet. Das Strömungsbild um den Meteorkörper wird durch ein parabolisches Modell approximiert und die sich daraus ergebenden Schlußfolgerungen mit den Ergebnissen anderer Autoren verglichen. Insbesondere zeigt die mittlere Temperatur eines solchen Modells eine gute Übereinstimmung mit den von CEPLECHA aus Meterorspektren berechneten Anregungstemperaturen. — Zur Abschätzung der Strahlungsverluste wird die spektrale Emission einer planparallelen Luftschicht von 1 und 10 cm Dicke für T = 23200, 58000 und 116000 °K und für verschiedene Luftdichten berechnet. Die Abweichungen von der Hohlraumstrahlung sind beträchtlich. Der hohe UV‐Anteil bewirkt eine Ionisation in der ungestörten Luft; die, STRÖMGRENsphäre kann dabei 10 bis 50 mal größer als der Meteorkörper sein. Eine Abschätzung für die Einstellzeit des Ionisationsgleichgewichts ergibt, daß sich die STRÖMGRENsphäre erst in einer von der Körperdimension abhängigen Mindesthöhe ausbilden kann. Die Ergebnisse der Kurzzeitmeteorbeobachtungen von BABADZHANOV und KRAMER könnten mit diesen Vorstellungen erklärt werden.
Physische Beobachtungen von Kometen. XV
Authors: Beyer M.
Published: July 2010

Als Fortsetzung von Nr. XIV dieser Serie [1] sind im folgenden die in den Jahren 1964–65 erhaltenen visuellen Beobachtungen der Kometen EVERHART (1964 h) und ALCOCK (1965 h) wiedergegeben. In beiden Fällen handelt es sich um Objekte, die auch im Perihel weit außerhalb der Erdbahn blieben und keine außergewöhnliche Entwicklung zeigten. Von einem um die Jahreswende 1964–65 erfolgten Lichtausbruch des periodischen Kometen SCHWASSMANN‐WACHMANN 1 (1925 II) konnte hier wegen ungünstiger Sichtbedingungen nur die letzte Phase erfaßt werden.
Weitere Messungen zur elliptischen Polarisation des kontinuierlichen Lichtes des Crab‐Nebels
Authors: Oetken L.
Published: July 2010

Die Wiederholung der Messungen zur Bestimmung der elliptischen Polarisation des kontinuierlichen Lichtes des Crab‐Nebels ergaben an keiner der untersuchten Nebelstellen eine verbürgte elliptische Polarisation.
Polarimetrische und kolorimetrische Untersuchungen am Crab‐Nebel II. Kolorimetrische Untersuchungen
Authors: Börngen F. , Chatschikjan E.
Published: July 2010

Es wird eine Dreifarbenphotometrie des Crab‐Nebels durchgeführt. Das Beobachtungsmaterial wurde im Winter 1962/63 mit der Tautenburger Schmidt‐Kamera gewonnen. Die Größe des Diaphragmas beträgt 7″.5 × 7″.5. Die Ergebnisse sind in einer Tabelle zusammengestellt. Diese enthält für etwa 3000 Flächenelemente die beobachteten Helligkeiten UT, BT und VT im System Tautenburg sowie die in das internationale Farbsystem transformierten Eigenfarben (U‐B)o und (B‐V)0.
Störungen und Bahnelemente im System ξ Ursae Maioris (Veröffentlichungen der Sternwarte München Band 7 Nr. 6)
Authors: Heintz W. D.
Published: July 2010

In den Beobachtungen von ADS 8119 äußert sich das unaufgelöste Untersystem nicht nur durch seine Bewegung, sondern auch merklich durch seine Störung der Bahnlage des sichtbaren Paares. Nach der Ermittlung spezieller Störungen erster Ordnung werden die visuellen und spektroskopischen Elemente und die Massen des vierfachen Sterns neu bestimmt. Die Parallaxe ist 0″.130.
Mittlere Kurven der elfjährigen und achtzigjährigen Zyklen der Sonnentätigkeit
Authors: Gleissberg W.
Published: July 2010

Curves showing the mean course of solar activity in 11‐year cycles with very low, low, high, and very high maxima and in 80‐year cycles with weak, moderate, and strong ascent or descent, respectively, are constructed. Their construction is based on the annual Wolf numbers from 1698 until 1964 and on the secularly smoothed values of Schove's auroral numbers for each decade from 331–340 until 1891–1900. The remarkable difference between the behaviour of the 11‐year cycles, on the one side, and the 80‐year cycles, on the other side, becomes quite evident from these curves. If Kopeck's interpretation of the 11‐year and 80‐year cycles is accepted, it follows that the rate of formation of the spot groups varies in an entirely other manner than their average life‐time.
Lichtelektrische Beobachtungen und Systemkonstanten des photometrischen Doppelsterns XZ Andromedae
Authors: Reinhardt Michael V.
Published: July 2010

Orbital elements and relative dimensions have been derived for the typical Algol‐type variable XZ And from photoelectric observations in B and V. The orbital eccentricity found by Blitzstein [1] could not be established.
Mitteilungen über neuentdeckte Veränderliche Sterne (S 9727–S 10152)
Authors: Hoffmeister C.
Published: July 2010

The list contains 426 new variables, for which some details and charts are given. The introduction gives some information about the objective of the whole work: to deliver materials for a thorough statistical investigation concerning number and distribution of variable stars within the Galaxy.
Zur Deutung der Wellenlängenabhängigkeit der interstellaren Extinktion
Authors: Friedemann R. , Schmidt K.‐H.
Published: July 2010

Es wird gezeigt, daß die von Stecher beobachtete Wellenlängenabhängigkeit der interstellaren Extinktion im Raketenultraviolett durch die Kombination von Eis‐ und Graphitteilchen befriedigend dargestellt werden kann, wenn die Verteilungsfunktion der Partikelradien der Eisteilchen ein abfallendes Exponentialgesetz und die der Graphitteilchen eine Gauss‐Verteilung ist. Die mittlere Teilchengröße beträgt für die Eispartikeln 6.0 · 10‐6 cm und für die Graphitteilchen 2.5 · 10‐6 cm. Der Anteil des Graphits beträgt nur 2 bis 4 Prozent an der Gesamtmasse des Staubes.

Unter dem unterschiedlichen Einfluß des Strahlungsdrucks auf Teilchen verschiedener Größe tritt in der Umgebung heißer Sterne eine Entmischung des interstellaren Staubes ein, wodurch eine Veränderung der Wellenlängenabhängigkeit der Extinktion besonders im ultravioletten Spektralbereich verursacht wird. Das im Oriongebiet beobachtete Verfärbungsgesetz kann damit zwanglos erklärt werden.

Der starke Anstieg der Extinktion im infraroten Bereich, wie er von Johnson gefunden wurde, läßt sich durch eine Verteilungsfunktion der Partikelradien verstehen, nach der Teilchen mit Radien von etwa 3 10‐4 cm relativ häufig sind.
Beobachtungsergebnisse der Berliner Arbeitsgemeinschaft für veränderliche Sterne e.V. (BAV)
Authors: Braune W. , Hübscher J.
Published: July 2010

In dieser 7. Zusammenstellung von Beobachtungsergebnissen werden 426 Minima von 75 Bedeckungssternen, 124 Maxima von 23 RR Lyrae‐ und δ Cephei‐Sternen, sowie 34 Maxima und 9 Minima von 15 Mira‐Sternen und langperiodischen Veränderlichen aus den Jahren 1963 bis 1965 mitgeteilt.
Zur Reduktion photographischer Sternpositionen bei mehrfacher Überdeckung des Feldes
Authors: De Vegt R.
Published: July 2010

Es wird ein strenger Ausgleichungsansatz für die Reduktion photographischer Sternpositionen angegeben, welcher die teilweise gegenseitige Überlappung der Platten direkt in den Bedingungsgleichungen für die Plattenkonstanten berücksichtigt. Die Anwendung auf ein Zufallssternfeld mit 1400 Sternen ergibt eine Erhöhung der Genauigkeit der resultierenden Feldsternörter um 10% gegenüber dem konventionellen Verfahren der Einzelausgleichung der Platten.
Solar Motion‐ and Galactic Rotation‐Terms from AGK 3 Proper Motions
Authors: Dieckvoss W.
Published: July 2010

In three tables results of a statistical study from 163811 stars grouped according to spectral type and apparent magnitude are presented for apex of solar motion, secular parallaxes, linear terms of differential galactic rotation. The latter are lying closely to the recommended preliminary values of + 15, ‐10 km/s/kpc.
Eine hypothesenfreie Bestimmung der Präzession und des Fundamental‐Koordinatensystems unter Verwendung des FK 4
Authors: Thüring Bruno , Thüring Eckart
Published: July 2010

Die in einer früheren Veröffentlichung (Astron. Nachr. 281. 49–58; 1952) gegebene Definition des astronomischen Fundamentalkoordinatensystems wird auf die Sterne des Katalogs FK4 angewandt. Ohne sich auf die Hypothese der Regellosigkeit der Pekuliarbewegungen stützen zu müssen, ergeben sich die folgenden Korrektionen der Newcombschen Präzessionskonstanten m und n: ‐0″.363 bzw. + 0″.048 pro Jahrhundert. Es wird zwischen einer innenbestimmten und einer außenbestimmten Genauigkeit unterschieden (§ 3).
Spectrophotometry of some lines in Beta Lyrae
Authors: Svolopoulos Sotirios N.
Published: July 2010

A spectrophotometric study of the spectral lines Hγ, He I λ 4388 Å, He I λ 4472 Å, Fe II λ 4352 Å and Mg II λ 4481 Å in the spectrum of β Lyrae has been made by using fifteen spectra taken with a spectrograph (8 Å/mm) attached to the 1‐metre reflector of the Hamburger Sternwarte. The profiles of the above lines are given. Also the probable variations of these profiles with time are examined on the basis of a comparison of our observational data with data existing in the literature. More attention was paid to the emission components of Hγ and the Helium lines.

The views previously described in a general way by Sahade as to the structure of the emission lines are rather supported.
Observation of the solar eclipse 1966 May 20 in the region between 3.2 cm to 2.7 m wavelength
Authors: Fürstenberg F. , Keiser J. , Priese J.
Published: July 2010

The solar eclipse 1966 May 20 was observed at 3.2, 10, 15, 20, 54, 59 cm, 1.05, 1.34 and 2.7 m wavelength by the observatories of the Heinrich‐Hertz‐Institut. The meter‐wavelength observations were superposed by a noise storm.

The result shows a region of enhanced radiation from the plages near the central meridian at the short wavelengths. Consulting additionally the observations made at Kiel, NERA, and Ondejov in the region of about 1.2 m wavelength it is possible to localize the source of the noise storm.
Das Alter des Trapez‐Haufens im Orion‐Nebel
Authors: Schöneich W.
Published: July 2010

Die Mitglieder des Trapez‐Haufens im Orion‐Nebel wurden auf Grund ihrer größeren Verfärbung von den Sternen der Schwert‐Gruppe getrennt. Das Farben‐Helligkeits‐Diagramm wurde mit den Modellreihen von Ezer und Cameron verglichen. Es ergibt sich ein Alter von etwa 2 ṁ 105 Jahren in guter Übereinstimmung mit dem Expansionsalter des Haufens und dem der HI‐Hülle des Nebels. Die Abschätzungen aus der Ionisationszone und aus der Expansion des Nebels selbst geben ein zu kleines Alter.
Zur Genauigkeit von Clemence' Theorie des Mars
Authors: Böhme S.
Published: July 2010

Die Autokovarianzfunktion der Differenzen in Länge zwischen Clemence' Theorie des Mars und der numerischen Integration von Herget zeigt, daß diese Widersprüche ein trigonometrisches Glied mit einer Periode von 724d und einer mittleren Amplitude von 0ṁ015 enthalten.
Das Farben‐Durchmesser‐ und Farben‐Helligkeits‐Diagramm der Virgo‐Galaxien
Authors: Oleak H.
Published: July 2010

Holmberg's photometric data of the Virgo cluster members are used to construct a color‐diameter and color‐magnitude diagram (figure 3). These diagrams show some characteristic features: 1. The late type spirals Sc — Sm are concentrated near a line — the Y‐branch — for which diameter and magnitude increase with increasing color index. 2. The early type spirals Sa — Sbc form the “X‐branch”, for which diameter and magnitude decrease for increasing color index. 3. Elliptical and lenticular galaxies show a large scatter in a small interval of colors. 4. The types Sa — Sbc are clearly separated in two groups (X and X́ in fig. 3).

Only the X‐ and Y‐branch probably belong to the main Virgo cloud (the mean velocity being the same), whereas the X́‐galaxies indicate the presence of a more distant cloud (the velocity is about 400 to 500 km/s larger). The distribution of the galaxies on the sky further shows some peculiarities of the X́‐galaxies (fig. 4). They are accumulated in two sectors around the cluster center and perhaps indicate a cloud expanding from the center or from the radio galaxy Virgo A. Without this cloud the plot of the remaining spiral galaxies reveals a color‐diameter and color‐magnitude diagram of relative small dispersion about the mean curves (fig. 5). It is suggested that other clusters may also possess such pronounced diagrams offering favourable possibilities to derive distance, structure and evolution effects. For the Virgo cluster the distance modulus is derived by means of Holmberg's data for M 31 (X‐galaxy) and M 33 (Y‐galaxy) using the distances of Sandage for the Local Group members. From both the diameter and magnitude the same value results: 31.15 ± 0·08. With the mean velocity of the investigated galaxies the Hubble parameter becomes H = (88 ± 9) km/s/Mpc.
Zur Polarisation der Strahlung von langperiodischen Veränderlichen
Authors: Schmidt K.‐H.
Published: July 2010

Assuming that graphite particles are responsible for the observed polarization in late‐type variables the sizes of the grains are derived to about 10−6 cm. Further it is shown that the lower limit for the strength of the magnetic field in the atmospheres of these stars lies between 0·3 and 10 Gauß.
Photographische Doppelsternmessungen aus den Jahren 1922 bis 1926
Authors: Münch W.
Published: July 2010

Es werden für 9 Doppelsternsysteme die Meßergebnisse von 19 Platten mitgeteilt, die in den Jahren 1922, 1924 und 1926 mit dem visuellen Objektiv am Doppelrefraktor des Astrophysikalischen Observatoriums Potsdam aufgenommen wurden.
Light‐curve inversions with truncated least‐squares principal components: Tests and application to HD 291095 = V1355 Orionis
Authors: Savanov I.S. , Strassmeier K.G.
Published: July 2010

We present a new inversion code that reconstructs the stellar surface spot configuration from the light curve of a rotating star. Our code employs a method that uses the truncated least‐squares estimation of the inverse problem's objects principal components. We use spot filling factors as the unknown objects. Various test cases that represent a rapidly‐rotating K subgiant are used for the forward problem. Tests are then performed to recover the artificial input map and include data errors and input‐parameter errors. We demonstrate the robustness of the solution to false input parameters like photospheric temperature, spot temperature, gravity, inclination, unspotted brightness and different spot distributions and we also demonstrate the insensitivity of the solution to spot latitude. Tests with spots peppered over the entire stellar surface or with phase gaps do not produce fake active longitudes. The code is then applied to ten years of V and I ‐band light curve data of the spotted sub‐giant HD291095. A total of 22 light curves is presented. We find that for most of the time its spots were grouped around two active longitudes separated on average by 180°. Switches of the dominant active region between these two longitudes likely occurred about every 3.15±0.23 years while the amplitude modulation of the brightness occurred with a possible period of 3.0±0.15 years. For the first time, we found evidence that the times of the activity flips coincide with times of minimum light as well as minimum photometric amplitude, i.e. maximum spottedness. From a comparison with simultaneous Doppler images we conclude that the activity flips likely take place near the rotational pole of the star. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamic OD estimation using three phase traffic flow theory
Authors: Lee Seungjae , Heydecker Benjamin , Kim Yong Hoon , Shon Eui‐Young
Published: July 2010

Advanced Transportation Management and Information Systems (ATMIS) can use dynamic origin–destination (OD) demand models to make short‐term predictions regarding developments in traffic states. However, existing dynamic OD prediction models do not achieve this reliably for two main reasons. First, this is a bi‐level system that consists of a traffic flow process at the lower level and a dynamic OD process at the upper level. Due to the inherent non‐convexity of bi‐level systems, it is difficult to guarantee that any calculated solution is globally optimal. In this paper, we propose a new traffic flow model that uses real‐time traffic data, such as traffic flows, speed and occupancy, collected from vehicle detectors, to address the difficulties that arise in existing bi‐level programming formulations. Second, in order to estimate a dynamic OD demand between on and off‐ramps on the freeways, a traffic flow model is needed to estimate the proportion of traffic moving between them. In this paper, we present a dynamic traffic estimation model based on Kerner's 1 three‐phase traffic theory, which represents the complexity of traffic phenomena based on phase transitions between free‐flow, synchronized flow and moving jam phases, and on their complex nonlinear spatio‐temporal features. The present model explains and estimates traffic congestion in terms of speed breakdown, phase transition and queue propagation. We show how a genetic algorithm can be used to solve this to estimate dynamic OD flows and the associated link, on and off‐ramp flows during each time interval using traffic data collected from vehicle detection systems implemented on Korean freeways. Copyright © 2010 John Wiley & Sons, Ltd.
Investigating effects of asphalt pavement conditions on traffic accidents in Tennessee based on the pavement management system (PMS)
Authors: Chan Chun Yip , Huang Baoshan , Yan Xuedong , Richards Stephen
Published: July 2010

Pavement maintenance is essential for ensuring good riding quality and avoiding traffic congestion, air pollution, and accidents. Improving road safety is one of the most important objectives for pavement management systems. This study utilized the Tennessee Pavement Management System (PMS) and Accident History Database (AHD) to investigate the relationship between accident frequency and pavement distress variables. Focusing on four urban interstates with asphalt pavements, divided median types, and 55 mph speed limits, 21 Negative Binomial Regression models were developed for predicting various types of traffic accident frequencies based on different pavement condition variables, including rut depth (RD), International Roughness Index (IRI), and Present Serviceability Index (PSI). The modeling results indicated that the RD models did not perform well, except for predicting accidents at night and accidents under rain weather conditions; whereas, IRI and PSI were always significant prediction variables in all types of accident models. Comparing the models goodness‐of‐fit results, it was found that the PSI models had a better performance in crash frequency prediction than the RD models and IRI models. This study suggests that the PSI accident prediction models should be considered as a comprehensive approach to integrate the highway safety factors into the pavement management system. Copyright © 2010 John Wiley & Sons, Ltd.
Short‐term exposure to a 1439‐MHz TDMA signal exerts no estrogenic effect in rats
Authors: Yamashita Hiroharu , Hata Keisuke , Yamaguchi Hironori , Tsurita Giichiro , Wake Kanako , Watanabe Soichi , Taki Masao , Ueno Shoogo , Nagawa Hirokazu
Published: July 2010

The aim of this study was to elucidate the possible effects of short‐term exposure to a 1439‐MHz electromagnetic field (EMF) employing time division multiple access (TDMA), which is the basis of the Japanese Personal Digital Cellular system, on estrogenic activity in rats. Sixty‐four ovariectomized female Sprague–Dawley rats were divided into four groups: EMF exposure (EM), sham exposure, cage control, and 17 beta‐estradiol injected (E2). The EM group was exposed, for 4 h per day on three consecutive days, to the 1439‐MHz TDMA signal that produced 5.5–6.1 and 0.88–0.99 W/kg average specific absorption rates in the brain and the whole body, respectively. The uterine wet mass and serum estradiol level significantly increased in the E2 group, while there were no differences among the other three groups. Although negative effects of long‐term EMF exposure must be thoroughly investigated before a final conclusion can be reached, our results do not support the assumption that the high frequency EMF used in cellular phones exerts estrogenic activity. Bioelectromagnetics 31:573–575, 2010. © 2010 Wiley‐Liss, Inc.
Assessment of general public exposure to LTE and RF sources present in an urban environment
Authors: Joseph Wout , Verloock Leen , Goeminne Francis , Vermeeren Günter , Martens Luc
Published: July 2010

For the first time, in situ electromagnetic field exposure of the general public to fields from long term evolution (LTE) cellular base stations is assessed. Exposure contributions due to different radiofrequency (RF) sources are compared with LTE exposure at 30 locations in Stockholm, Sweden. Total exposures (0.2–2.6 V/m) satisfy the International Commission on Non‐Ionizing Radiation Protection (ICNIRP) reference levels (from 28 V/m for frequency modulation (FM), up to 61 V/m for LTE) at all locations. LTE exposure levels up to 0.8 V/m were measured, and the average contribution of the LTE signal to the total RF exposure equals 4%. Bioelectromagnetics 31:576–579, 2010. © 2010 Wiley‐Liss, Inc.
Resveratrol: Biological and pharmaceutical properties as anticancer molecule
Authors: Hsieh Tze‐chen , Wu Joseph M.
Published: July 2010

There is ample evidence that shows an inverse relationship between consumption of fruit/vegetable‐rich diets and the risk of cancer at various anatomical sites. In this review, we will assess and summarize recent advances on cancer prevention by resveratrol, a natural stilbenoid present in red grapes, peanuts, some common drinks, and dietary supplements. We will focus on data published within the past few years on in vivo model tumor animal studies that reinforce the chemopreventive efficacy of resveratrol against a multitude of cancers, as well as on its sensitization/enhancing activities against tumor cells when used in combination with established chemotherapeutic and pharmaceutical agents. In addition, we will review examples resveratrol‐target proteins, denoted RTPs, including the 24‐kDa cytosolic protein quinone reductase 2 (NQO2) discovered in our laboratory that may confer resveratrol responsiveness to cancer cells. We will discuss the possible role of NQO2 in mediating cancer prevention by resveratrol. Our analysis of published data strengthen support that resveratrol displays novel roles in various cellular processes, and help to establish an expanded molecular framework for cancer prevention by resveratrol in vivo.
Cytokine regulation of natural killer cell effector functions
Authors: Zwirner Norberto W. , Domaica Carolina I.
Published: July 2010

Initially described as effectors of natural cytotoxicity and critical players for the control of viral infections and tumor growth, recent investigations unraveled more widespread functions for the natural killer (NK) cells. Through the establishment of a crosstalk with dendritic cells, NK cells promote T helper‐1‐ and cytotoxic T lymphocyte‐mediated immunity, whereas through the establishment of a crosstalk with macrophages, NK cells contribute to the activation of their microbicidal functions. Recent evidence has shown that NK cells also display memory, a characteristic thought to be privative of T and B cells, and that NK cells acquire their mature phenotype during a complex ontogeny program which tunes their activation threshold. Cytokines play critical roles in regulating all aspects of immune responses, including lymphoid development, homeostasis, differentiation, tolerance, and memory. Cytokines such as interleukin (IL)‐2, IL‐12, IL‐15, IL‐18, IL‐21, and type I interferons constitute pivotal factors involved in the maturation, activation, and survival of NK cells. In addition, the discovery of novel cytokines is increasing the spectrum of soluble mediators that regulate NK cell immunobiology. In this review, we summarize and integrate novel concepts about the role of different cytokines in the regulation of NK cell function. We believe that a full understanding of how NK cells become activated and develop their effector functions in response to cytokines and other stimuli may lead to the development of novel immunotherapeutic strategies for the treatment of different types of cancer, viral infections, and chronic autoimmune diseases.
The anatomy of the superior labrum and biceps origin in the fetal shoulder
Authors: Lapner Peter L.C. , Lapner Michael A. , Uhthoff Hans K.
Published: July 2010

The presence of a sublabral recess has been observed in adult shoulders. It is unclear whether this occurrence is a developmental variation or is acquired. The primary objective of the study was to determine if a cleft exists between the superior labrum and the superior cartilaginous glenoid anlage during the second trimester. The secondary objective was to define the origin of the long head of the biceps in the human fetus in the second trimester. Shoulders of 11 fetuses, 11–20 weeks old, were sectioned in the coronal plane. The superior labrum was observed to be continuous with the superior glenoid anlage, and a cleft was not observed at any stage of development. The biceps tendon originated from the superior labrum and the superior glenoid tubercle anlage in all specimens. Fibers extending in the direction of superior glenoid tubercle anlage were always very prominent. Clin. Anat. 23:821–828, 2010. © 2010 Wiley‐Liss, Inc.
Long‐term clinical benefit of drug‐eluting stents over bare‐metal stents in diabetic patients with de novo left main coronary artery disease: Results from a real‐world multicenter registry
Authors: Capodanno Davide , Di Salvo Maria Elena , Palmerini Tullio , Sheiban Imad , Margheri Massimo , Vecchi Giuseppe , Sangiorgi Giuseppe , Piovaccari Giancarlo , Bartorelli Antonio , Briguori Carlo , Ardissino Diego , Di Pede Francesco , Ramondo Angelo , Inglese Luigi , Petronio Anna Sonia , Bolognese Leonardo , Benassi Alberto , Palmieri Cataldo , Filippone Vincenzo , De Servi Stefano , Tamburino Corrado
Published: July 2010

Background: Few data are available on diabetic patients undergoing percutaneous coronary intervention (PCI) in the context of unprotected left main coronary artery (ULMCA) disease. The main goal of this study was to present the long‐term relative benefits of using drug‐eluting stent (DES) instead of bare‐metal stent (BMS) for diabetic patients submitted to percutaneous ULMCA treatment in a large real world multicenter registry. Methods: The GISE‐SICI registry is a retrospective, observational multicenter registry promoted by the Italian Society of Invasive Cardiology in which 19 high‐volume participating centers enrolled 1,453 consecutive patients who underwent PCI on ULMCA between January 2002 and December 2006. From the registry, a total of 398 consecutive patients with diabetes mellitus who underwent DES (n = 321) or BMS (n = 77) implantation were analyzed, with extensive multivariable adjustments. Results: At 3‐years, use of DES in diabetic patients resulted in no significant differences with respect to death (HR 0.56, 95% CIs 0.24–1.28), myocardial infarction (HR 0.82, 95% CIs 0.21–3.26), and the composite end‐point of death or myocardial infarction (HR 0.56, 95% CIs 0.27–1.20). Conversely, DES were associated with significant reduction of target lesion revascularization (TLR, HR 0.33; 95% CIs 0.14–0.80, P = 0.001) rates. Conclusions: Patients presenting with ULMCA disease in the context of diabetes mellitus who are treated with stent‐supported PCI have a significant reduction in the rate of TLR with no increased risk of death or myocardial infarction. © 2009 Wiley‐Liss, Inc.
Selective Lanthanides Sequestration Based on a Self‐Assembled Organosilica
Authors: Besson Eric , Mehdi Ahmad , Van der Lee Arie , Chollet Hervé , Reyé Catherine , Guilard Roger , Corriu Robert J. P.
Published: July 2010

In this paper, we investigate the cation‐exchange properties of a self‐assembled hybrid material towards trivalent ions, lanthanides (La3+, Eu3+, Gd3+, Yb3+) and Fe3+. The bis‐zwitterionic lamellar material was prepared by sol–gel process from only 3‐aminopropyltriethoxysilane (APTES), succinic anhydride, and ethylenediamine. In ethanol heated under reflux, the exchange ethylenediammonium versus Ln3+ proved to be complete by complexometry measurements and elemental analyses, one Cl− ion per one LnIII remaining as expected for charge balance. In aqueous solution at 20 °C, the material was found to be selective towards lanthanide in spite of the similarity of their ionic radii. The cation uptake depends on the nature of the salt, the difference between two lanthanides reaching up to 20 % in some cases. Finally, ion‐exchange reaction with FeCl3 was chosen as a probe to get more information on the material after incorporation of trivalent ions. Based on Mössbauer spectroscopic investigations on the resulting material in conjunction with the XRD analysis of materials containing trivalent ions, a structural model was proposed to describe the incorporation of trivalent ions by exchange reaction within the original zwitterionic material.
The Influence of Phosphane Ligands on the Versatility of Ruthenium–Indenylidene Complexes in Metathesis
Authors: Broggi Julie , Urbina‐Blanco César A. , Clavier Hervé , Leitgeb Anita , Slugovc Christian , Slawin Alexandra M. Z. , Nolan Steven P.
Published: July 2010

The aim of the present study is to develop readily available and stable pre‐catalysts that could be easily prepared on large scale from simple starting materials. Based on the hypothesis that substitution of classical PCy3 with phosphanes of varying electron‐donating properties could be a straightforward manner to improve catalytic activity, a methodical study dealing with the effect of phosphane fine‐tuning in ruthenium–indenylidene catalysts was performed. Challenged to establish how the electronic properties of para‐substituted phosphane ligands translate into catalyst activity, the versatile behaviour of these new ruthenium–indenylidene complexes was investigated for a number of metathesis reactions.
Recent Mechanistic and Synthetic Developments in the Chemistry of Transition‐Metal Vinylidene Complexes
Authors: Lynam Jason M.
Published: July 2010

Transition‐metal vinylidene complexes are intermediates in a number of synthetically important transformations of alkynes. Underpinning these applications is the ability of various electron‐rich transition‐metal complexes to effectively facilitate the conversion of alkynes into their vinylidene tautomers. Recent experimental and theoretical studies have provided considerable insight into the mechanisms by which this process occurs and they are detailed herein. In particular, it has been demonstrated that different substituents on both the metal and the alkyne may have profound effects on both the kinetic and thermodynamic profiles of the alkyne/vinylidene tautomerisation. An important finding is that internal alkynes may be employed to prepare disubstituted vinylidene complexes under easily accessible conditions. This discovery brings to light a new facet of the potential synthetic applications of transition metal vinylidene complexes.
Rational Design of Nanofibers and Nanorings through Complementary Hydrogen‐Bonding Interactions of Functional π Systems
Authors: Yagai Shiki , Aonuma Hiroaki , Kikkawa Yoshihiro , Kubota Shun , Karatsu Takashi , Kitamura Akihide , Mahesh Sankarapillai , Ajayaghosh Ayyappanpillai
Published: July 2010

A simple protocol to create nanofibers and ‐rings through a rational self‐assembly approach is described. Whereas the melamine–oligo(p‐phenylenevinylene) conjugate 1 a self‐aggregates to form ill‐defined nanostructures, conjugate 1 b, which possesses an amide group as an additional interactive site, self‐aggregates to form 1D nanofibers that induce gelation of the solvent. AFM and XRD studies have shown that dimerization through the melamine–melamine hydrogen‐bonding interaction occurs only for 1 b. Upon complexation with 1/3 equivalents of cyanuric acid (CA), conjugate 1 a provides well‐defined, ring‐shaped nanostructures at micromolar concentrations, which open to form fibrous assemblies at submillimolar concentrations and organogels in the millimolar concentration range. Apparently, the enhanced aggregation ability of 1 a by CA is a consequence of columnar organization of the resulting discotic complex 1 a3⋅CA. In contrast, coaggregation of 1 b with CA does not provide well‐defined nanostructures, probably due to the interference of complementary hydrogen‐bonding interactions by the amide group.
ChemInform Abstract: Energetics of C20 and C22 Fullerene and Near‐Fullerene Carbon Cages
Authors: DOMENE M. C. , FOWLER P. W. , MITCHELL D. , SEIFERT G. , ZERBETTO F.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis and Crystal Structure of Cs3Y7Se12.
Authors: FOLCHNANDT M. , SCHLEID T.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Oxidation States, Transport Properties, and Te×××Te Short Contacts in the Ternary Transition Metal Tellurides Ta3Pd3Te14 and Ta4Pd3Te16.
Authors: ALEMANY P. , JOBIC S. , BREC R. , CANADELL E.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Defect Chemistry of Donor‐Doped and Undoped Strontium Titanate Ceramics Between 1000 ° and 1400 °C.
Authors: MOOS R. , HAERDTL K. H.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Ferromagnetic Perovskites in the System LaMn1‐xGaxO3 Stabilized by Dynamic Jahn—Teller Deformations.
Authors: TOEPFER J. , GOODENOUGH J. B.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The STM Imaging of an Ordered (AuCl3)2 Surface Species During Chloride‐Induced Dissolution of Au(111).
Authors: HAISS W. , SASS J.‐K.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Ammonolysis Reaction of (NH4)2GeF6. Synthesis and Structure of NH4[Ge(NH3)F5].
Authors: WEBER W. , SCHWEDA E.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Iron‐Substituted Dawson‐Type Tungstodiphosphates: Synthesis, Characterization, and Single or Multiple Initial Electronation Due to the Substituent Nature or Position.
Authors: CONTANT R. , ABBESSI M. , CANNY J. , BELHOUARI A. , KEITA B. , NADJO L.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The Thermal Decomposition of an Organometallic Precursor for the Preparation of YBa2Cu3O7‐x.
Authors: BINDER J. R. , WEDEMEYER H. , REUTER H.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Charge Delocalization Pathways in Persistent 1‐Pyrenyl‐, 4‐Pyrenyl‐, and 2‐Pyrenylmethylcarbenium Ions as Models of PAH‐Epoxide Ring Opening: NMR Studies in Superacids and AM1 Calculations.
Authors: LAALI K. K. , HANSEN P. E.
Published: July 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.