Huemmerich, Stefan; Bernhard, Klaus
Under favourable circumstances, transits of known exoplanets with large amplitudes like WASP-18 b can be observed in the ASAS-3 database. An attempt to search for exoplanets using ASAS-3 data is discussed.
On the occasion of the 250th birthday of Johann Hieronymus Schroeter (1745 - 1816), a collection of reprints has been published. This collection contains articles on solar observations made by Schroeter and other astronomers of his time.
Biologie und Fremdsprachenunterricht. Das Prinzip der Einsprachigkeit im Lichte biologischer Erkenntnisse ueber Denken und Lernen (Biology and Foreign Language Teaching. The Monolingual Principle in the Light of Biological Findings concerning Thinking and Learning).
Draws upon recent publications dealing with brain function (particularly F. Vester, "Denken, Lernen, Vergessen", Munich, 1978) for ideas for foreign language teaching. These include constant use of the foreign language in the classroom, frequent repetition, and avoidance of false associations by explanation in the native language. (IFS/WGA)
Grüneberg, Björn; Ostendorp, Wolfgang; Leßmann, Dieter; Wauer, Gerlinde; Nixdorf, Brigitte
Süßwasserseen haben als ökosysteme und Lebensraum für Pflanzen und Tiere eine herausragende Bedeutung für die Artenvielfalt auf der Erde und prägen als Landschaftselemente unsere natürliche Umwelt. Seen fungieren als natürliche Stoffsenken, vor allem für Kohlenstoff und Nährstoffe, aber auch als Senken für in ihren Einzugsgebieten emittierte gelöste und feste Schadstoffe. Darüber hinaus ist Wasser eine wichtige Naturressource. Süßwasserseen stellen in den meisten Regionen der Erde lebenswichtige Quellen für die Versorgung mit Trinkwasser und tierischem Eiweiß (Fischfang) dar. Sie dienen als Wasserspeicher für die landwirtschaftliche und industrielle Nutzung. Auch für Erholungsaktivitäten des Menschen kommt ihnen eine große Bedeutung zu.
Liou, B.-T.; Wu, C.-Y.
A study of the application of the discrete-ordinate method (DOM) with remedy for the ray effects to the solution of surface radiation exchange is presented in this paper. The remedy for the ray effects is achieved by dividing the radiative intensity into the attenuated incident and the medium emitting components. To demonstrate the application of the technique, this work considers radiative heat transfer in a two-dimensional cylindrical enclosure filled with a nearly transparent medium. The results obtained by the present DOM are in excellent agreement with those by the radiosity/irradiation method. Zusammenfassung In der Arbeit wird ein Weg aufgezeigt, wie die Störstrahlungseffekte bei Anwendung der Methode der diskreten Ordinaten auf die Berechnung des Energietausches zwischen Oberflächenstrahlern vermieden werden können. Dies läßt sich durch Aufspaltung der Strahlungsintensität in die abgeschwächte einfallende und die vom Medium emittierte Komponente erreichen. Als Beispiel für die Anwendung dieses Verfahrens dient der Wärmeaustausch durch Strahlung in einem zweidimensionalen zylindrischen Behältnis, das mit einem nahezu transparenten Medium befüllt ist. Die mit der modifizierten Methode erhaltenen Ergebnisse stimmen ausgezeichnet mit jenen nach dem klassischen Brutto-Verfahren überein.
Brand, Richard A
This biographical sketch on Julius Wolff corresponds to a translation of the historic text, Zur Lehre von der Fracturenheilung, available at DOI 10.1007/s11999-010-1240-9 ; and a translation and abridgement of the historic text, Ueber die Innere Architectur der Knochen und ihre Bedeutung für die Frage vom Knochenwachstum, available at DOI 10.1007/s11999-010-1239-2 . (Supplemental materials are available with the online version of CORR.) An accompanying Editorial is available at DOI 10.1007/s11999-010-1238-3 . PMID:20151232
This Classic Article is a translation of the original work by Franz König, "Ueber freie Körper in den Gelenken" [On loose bodies in the joint]. Dtsch Z Chir. 1887;27: 90-109. available at DOI 10.1007/s11999-013-2824-y (Translated by Drs. Richard A. Brand and Christian-Dominik Peterlein). An accompanying biographical sketch of F. König is available at DOI 10.1007/s11999-013-2823-z . A PDF of the original German is available as supplemental material. (ED Note: An attempt has been made to preserve some of the original wording while placing the material in a contemporary context. In some cases the author's original intent was obscure.). PMID:23404416
The Dachstein Limestone of the Northern Calcareous Alps contains massive limestone beds, capped by dolomitic horizons. Groups of beds form bundles or stratification cycles and spectral analysis gives evidence of at least 3 orders of cycle frequencies. The regularity in the repetition of the limestones and dolomites was first pointed out by Sander (1936) [Sander, B., 1936. Beitrage zur Kenntniss der Anlagerungsgefuege. Mineral. Petrogr. Mitt. 48, 27-139] and the repetition of definite groups by Schwarzacher (1948, 1954) [Schwarzacher, W., 1948. Ueber die sedimentaere Rhytmik des Dachstein Kalkes von Lofer. Verh. Geol. Bundesanst. 1947 (Heft 10-12), 176-188; Schwarzacher, W., 1954. Ueber die Grossrhytmik des Dachstein Kalkes von Lofer. Tschermaks Mineral. Petrogr. Mitt. 4, 44-54]. The facies associated with the change from limestone to dolomite was interpreted by Fischer (1964) [Fischer, A.G., 1964. The Lofer cyclothems of the alpine Triassic. In: Merriam, D.F. (Ed), Symposium on Cyclic Sedimentation. Kansas Geological Survey Bull. 169, 107-146] as an environmental change from lagoonal to peritidal and consequently as evidence of rising and falling sea level. The present paper is based on the study of over 500 aerial photographs from the Loferer and Leoganger Steinberge and also on a detailed section, measured by Paul Enos and E. Samankassou in the Steinernes Meer. It was found that the Dachstein Limestone from Lofer and Leogang comprised about 35 stratification cycles of approximately 20 m thickness. This may correspond to a similar number of cycles in the Steinernes Meer where the spectral analysis gave a cycle thickness of 27 m and 13.6 m. The interpretation of the bundle as being caused by the 100 ka eccentricity cycle is considered tenable.
Boveri's visionary monograph ‘Ueber die Natur der Centrosomen’ (On the nature of centrosomes) in 1900 was founded primarily on microscopic observations of cleaving eggs of sea urchins and the roundworm parasite Ascaris. As Boveri wrote in the introductory paragraph, his interests were less about morphological aspects of centrosomes, but rather aimed at an understanding of their physiological role during cell division. The remarkable transition from observations of tiny dot-like structures in fixed and sectioned material to a unified theory of centrosome function (which in essence still holds true today) cannot be fully appreciated without examining Boveri's starting material, the histological specimens. It was generally assumed that the microscope slides were lost during the bombing of the Zoological Institute in Würzburg at the end of WWII. Here, I describe the discovery of a number of Boveri's original microscope slides with serial sections of early sea urchin and Ascaris embryos, stained by Heidenhain's iron haematoxylin method. Some slides bear handwritten notes and sketches by Boveri. Evidence is presented that the newly discovered slides are part of the original material used by Boveri for his seminal centrosome monograph. PMID:25047623
Liu, Daniel; Ellis, Harold
The thymus is the last organ in the human body to have its mechanisms fully understood, having had its function fully delineated more than 50 years ago (Miller , Tissue Antigens 63:509-517). Prior to this, the thymus gland has had an interesting history with theories having included a role in fetal growth and development before becoming more sinisterly, a cause of sudden infant death in the late 19th century known as status lymphaticus (Paltauf , Wien Klin Wochenschr 2:877-881). Until Miller (, Lancet 278:748-749) eventually proved its primarily immunological role, the history of this mysterious gland has closely mirrored the history of medicine itself, troubling the minds of pathologists such as Virchow (, Ueber die Chlorose und die damit zusammenhängenden Anomalien im Gefässapparate, insbesondere über "Endocarditis puerperalis," vorgetragen in der Sitzung der Berliner Geburtshülflichen Gesellschaft vom 12) and Grawitz (, Deut Med Wochenschr 22:429-431), surgeons such as Astley Cooper (, The Anatomy of the Thymus Gland) and Keynes (1953, Ann R Coll Surg 12:88), and eminent medical epidemiologists such as Greenwood and Woods [, J Hyg (Lond) 26:305-326]. This article will hopefully be of interest therefore to both clinician and historian alike. Clin. Anat. 29:679-684, 2016. © 2016 Wiley Periodicals, Inc. PMID:27037529
Boveri's visionary monograph 'Ueber die Natur der Centrosomen' (On the nature of centrosomes) in 1900 was founded primarily on microscopic observations of cleaving eggs of sea urchins and the roundworm parasite Ascaris. As Boveri wrote in the introductory paragraph, his interests were less about morphological aspects of centrosomes, but rather aimed at an understanding of their physiological role during cell division. The remarkable transition from observations of tiny dot-like structures in fixed and sectioned material to a unified theory of centrosome function (which in essence still holds true today) cannot be fully appreciated without examining Boveri's starting material, the histological specimens. It was generally assumed that the microscope slides were lost during the bombing of the Zoological Institute in Würzburg at the end of WWII. Here, I describe the discovery of a number of Boveri's original microscope slides with serial sections of early sea urchin and Ascaris embryos, stained by Heidenhain's iron haematoxylin method. Some slides bear handwritten notes and sketches by Boveri. Evidence is presented that the newly discovered slides are part of the original material used by Boveri for his seminal centrosome monograph. PMID:25047623
Nyhart, Lynn K; Lidgard, Scott
Rudolf Leuckart's 1851 pamphlet Ueber den Polymorphismus der Individuen (On the polymorphism of individuals) stood at the heart of naturalists' discussions on biological individuals, parts and wholes in mid-nineteenth-century Britain and Europe. Our analysis, which accompanies the first translation of this pamphlet into English, situates Leuckart's contribution to these discussions in two ways. First, we present it as part of a complex conceptual knot involving not only individuality and the understanding of compound organisms, but also the alternation of generations, the division of labor in nature, and the possibility of finding general laws of the organic world. Leuckart's pamphlet is important as a novel attempt to give order to the strands of this knot. It also solved a set of key biological problems in a way that avoided some of the drawbacks of an earlier teleological tradition. Second, we situate the pamphlet within a longer trajectory of inquiry into part-whole relations in biology from the mid-eighteenth century to the present. We argue that biological individuality, along with the problem-complexes with which it engaged, was as central a problem to naturalists before 1859 as evolution, and that Leuckart's contributions to it left a long legacy that persisted well into the twentieth century. As biologists' interests in part-whole relations are once again on the upswing, the longue durée of this problem merits renewed consideration. PMID:21308403
Szereszewski, A.; Sym, A.
The standard method of separation of variables in PDEs called the Stäckel-Robertson-Eisenhart (SRE) approach originated in the papers by Robertson (1928 Math. Ann. 98 749-52) and Eisenhart (1934 Ann. Math. 35 284-305) on separability of variables in the Schrödinger equation defined on a pseudo-Riemannian space equipped with orthogonal coordinates, which in turn were based on the purely classical mechanics results by Paul Stäckel (1891, Habilitation Thesis, Halle). These still fundamental results have been further extended in diverse directions by e.g. Havas (1975 J. Math. Phys. 16 1461-8 J. Math. Phys. 16 2476-89) or Koornwinder (1980 Lecture Notes in Mathematics 810 (Berlin: Springer) pp 240-63). The involved separability is always ordinary (factor R = 1) and regular (maximum number of independent parameters in separation equations). A different approach to separation of variables was initiated by Gaston Darboux (1878 Ann. Sci. E.N.S. 7 275-348) which has been almost completely forgotten in today’s research on the subject. Darboux’s paper was devoted to the so-called R-separability of variables in the standard Laplace equation. At the outset he did not make any specific assumption about the separation equations (this is in sharp contrast to the SRE approach). After impressive calculations Darboux obtained a complete solution of the problem. He found not only eleven cases of ordinary separability Eisenhart (1934 Ann. Math. 35 284-305) but also Darboux-Moutard-cyclidic metrics (Bôcher 1894 Ueber die Reihenentwickelungen der Potentialtheorie (Leipzig: Teubner)) and non-regularly separable Dupin-cyclidic metrics as well. In our previous paper Darboux’s approach was extended to the case of the stationary Schrödinger equation on Riemannian spaces admitting orthogonal coordinates. In particular the class of isothermic metrics was defined (isothermicity of the metric is a necessary condition for its R-separability). An important sub-class of isothermic metrics
results are Kurt Godel's seminal paper in 1931: "Ueber formal unentscheidbare Saetze der Principia Mathematica and verwandter System I" and Arrow's Nobel Prize winning "Impossibility Theorem" (Social Choice and Individual Values, 1951). Godel showed, unequivocally, that there is an enormous gap between what is being perceived as truth and what in fact can be proven as such. Arrow showed that the translation of individual preferences into a social order is impossible--except in a dictatorship. The unsolved controversies concerning the desirable or ideal structure of health care systems are impinged upon by these findings generally, and, in the case of the impossibility theorem, also directly. There is the impossibility of aggregating preferences and, at a deeper level, the impossibility of defining certain fundamental values, coupled with the problematic use of certain words, the absence of the possibility of creating, on a logically defined base, a complex system, complete and comprehensive in its own right. This is added to the fact that according to the elaboration by Stephen Wolfram in "A New Kind of Science", it is not easy to reduce complicated systems to simple components and to predict the continuation of their development even from simple basic laws without complicated calculations. All of these factors impede the construction of satisfying health care systems and leave obvious problems which overshadow the structure and the operation of health care systems. PMID:15143703
This paper describes the historical background and early formation of Wilhelm Johannsen's distinction between genotype and phenotype. It is argued that contrary to a widely accepted interpretation (For instance, W. Provine, 1971. The Origins of Theoretical Population Genetics. Chicago: The University of Chicago Press; Mayr, 1973; F. B. Churchill, 1974. Journal of the History of Biology 7: 5-30; E. Mayr, 1982. The Growth of Biological Thought, Cambridge: Harvard University Press; J. Sapp, 2003. Genesis. The Evolution of Biology. New York: Oxford University Press) his concepts referred primarily to properties of individual organisms and not to statistical averages. Johannsen's concept of genotype was derived from the idea of species in the tradition of biological systematics from Linnaeus to de Vries: An individual belonged to a group - species, subspecies, elementary species - by representing a certain underlying type (S. Müller-Wille and V. Orel, 2007. Annals of Science 64: 171-215). Johannsen sharpened this idea theoretically in the light of recent biological discoveries, not least those of cytology. He tested and confirmed it experimentally combining the methods of biometry, as developed by Francis Galton, with the individual selection method and pedigree analysis, as developed for instance by Louis Vilmorin. The term "genotype" was introduced in W. Johannsen's 1909 (Elemente der Exakten Erblichkeitslehre. Jena: Gustav Fischer) treatise, but the idea of a stable underlying biological "type" distinct from observable properties was the core idea of his classical bean selection experiment published 6 years earlier (W. Johannsen, 1903. Ueber Erblichkeit in Populationen und reinen Linien. Eine Beitrag zur Beleuchtung schwebender Selektionsfragen, Jena: Gustav Fischer, pp. 58-59). The individual ontological foundation of population analysis was a self-evident presupposition in Johannsen's studies of heredity in populations from their start in the early 1890s till his